Hi. Im running with the 2008 Vol 1 in VS2005, and have a strange intermittant problem with one of the ultragrids.

 As a bit of background, I'm using a backgroundworker to populate a Dataset that the grid is being bound to. Due to issues previously with this, I have been binding the UG to an empty copy of the dataset, in order to prevent errors whilst populating it, and to keep the layout intact.

This has been working fine until I started adding  filters to the mix. Basically, when the BGW is about to be called, I check various fields for content, and build an SQL Where string based on that, which is stored as a class variable (to get past the issue with referencing objects from outside the UI thread). Now, I get an  "Object reference not set to an instance of an object." from the Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams) method.

 However, the strange thing is that its intermittant. I can add filter content to the form, and run the query. Sometimes it will run fine a couple of times, and sometimes it will just die with this error? Nothing is changed between runs.

 I've included the error details below, any ideas?:

 See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.NullReferenceException: Object reference not set to an instance of an object.
   at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
   at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
   at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
   at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
   at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
   at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
   at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
   at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
   at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
   at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
   at Infragistics.Win.UIElement.DrawHelper(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode, Boolean clipText, Boolean forceDrawAsFocused, Boolean preventAlphaBlendGraphics)
   at Infragistics.Win.UIElement.Draw(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode, Boolean forceDrawAsFocused, Boolean preventAlphaBlendGraphics)
   at Infragistics.Win.ControlUIElementBase.Draw(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode, Size elementSize, Boolean preventAlphaBlendGraphics)
   at Infragistics.Win.ControlUIElementBase.Draw(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode, Size elementSize)
   at Infragistics.Win.ControlUIElementBase.Draw(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode)
   at Infragistics.Win.UltraWinGrid.UltraGridUIElement.Draw(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode)
   at Infragistics.Win.UltraControlBase.OnPaint(PaintEventArgs pe)
   at Infragistics.Win.UltraWinGrid.UltraGrid.OnPaint(PaintEventArgs pe)
   at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer, Boolean disposeEventArgs)
   at System.Windows.Forms.Control.WmPaint(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///c:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
Microsoft.VisualStudio.HostingProcess.Utilities
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.42
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Microsoft.VisualStudio.HostingProcess.Utilities/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualStudio.HostingProcess.Utilities.dll
----------------------------------------
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
Microsoft.VisualStudio.HostingProcess.Utilities.Sync
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.42
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Microsoft.VisualStudio.HostingProcess.Utilities.Sync/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualStudio.HostingProcess.Utilities.Sync.dll
----------------------------------------
vshost
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.42
    CodeBase: file:///C:/SVN/Orbit/Orbit/bin/Debug/Orbit.vshost.exe
----------------------------------------
ADODB
    Assembly Version: 7.0.3300.0
    Win32 Version: 7.10.6030
    CodeBase: file:///C:/WINDOWS/assembly/GAC/ADODB/7.0.3300.0__b03f5f7f11d50a3a/ADODB.dll
----------------------------------------
System.Data
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.Data/2.0.0.0__b77a5c561934e089/System.Data.dll
----------------------------------------
System.Deployment
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Deployment/2.0.0.0__b03f5f7f11d50a3a/System.Deployment.dll
----------------------------------------
System.Design
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Design/2.0.0.0__b03f5f7f11d50a3a/System.Design.dll
----------------------------------------
System.Runtime.Serialization.Formatters.Soap
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Runtime.Serialization.Formatters.Soap/2.0.0.0__b03f5f7f11d50a3a/System.Runtime.Serialization.Formatters.Soap.dll
----------------------------------------
System.Web
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.Web/2.0.0.0__b03f5f7f11d50a3a/System.Web.dll
----------------------------------------
System.Xml
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
Infragistics2.Excel.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Excel.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Excel.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinDataSource.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinDataSource.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinDataSource.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinGrid.ExcelExport.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinGrid.ExcelExport.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinGrid.ExcelExport.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinTabbedMdi.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinTabbedMdi.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinTabbedMdi.v8.1.dll
----------------------------------------
Infragistics2.Shared.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Shared.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Shared.v8.1.dll
----------------------------------------
Infragistics2.Win.Misc.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.Misc.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.Misc.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinEditors.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinEditors.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinEditors.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinExplorerBar.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinExplorerBar.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinExplorerBar.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinGrid.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinGrid.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinGrid.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinStatusBar.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinStatusBar.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinStatusBar.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinTabControl.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinTabControl.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinTabControl.v8.1.dll
----------------------------------------
Infragistics2.Win.UltraWinToolbars.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.UltraWinToolbars.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.UltraWinToolbars.v8.1.dll
----------------------------------------
Infragistics2.Win.v8.1
    Assembly Version: 8.1.20081.1000
    Win32 Version: 8.1.20081.1000
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Infragistics2.Win.v8.1/8.1.20081.1000__7dd5c3163f2cd0cb/Infragistics2.Win.v8.1.dll
----------------------------------------
Microsoft.VisualBasic
    Assembly Version: 8.0.0.0
    Win32 Version: 8.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Microsoft.VisualBasic/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
Orbit
    Assembly Version: 0.0.1.0
    Win32 Version: 0.0.1.0
    CodeBase: file:///C:/SVN/Orbit/Orbit/bin/Debug/Orbit.EXE
----------------------------------------
System.Runtime.Remoting
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Runtime.Remoting/2.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------
System.Configuration
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
Infragistics.License
    Assembly Version: 1.0.5005.10
    Win32 Version: 1.0.5005.10
    CodeBase: file:///C:/WINDOWS/assembly/GAC/Infragistics.License/1.0.5005.10__7dd5c3163f2cd0cb/Infragistics.License.dll
----------------------------------------
Accessibility
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Accessibility/2.0.0.0__b03f5f7f11d50a3a/Accessibility.dll
----------------------------------------
System.Transactions
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.Transactions/2.0.0.0__b77a5c561934e089/System.Transactions.dll
----------------------------------------
System.EnterpriseServices
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.EnterpriseServices/2.0.0.0__b03f5f7f11d50a3a/System.EnterpriseServices.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.