Our application uses 10.1.20101.2013 build of WinForms. Our customers reporting, the same crash, that originates from UltraWinToolbars. The crash occurs randomly but on a regular basis. Below is the stack trace:

 ************** Exception Text **************
System.ArgumentException: Parameter is not valid.
   at System.Drawing.Graphics.GetHdc()
   at System.Windows.Forms.Internal.WindowsGraphics.FromGraphics(Graphics g, ApplyGraphicsProperties properties)
   at System.Windows.Forms.WindowsGraphicsWrapper..ctor(IDeviceContext idc, TextFormatFlags flags)
   at System.Windows.Forms.TextRenderer.MeasureText(IDeviceContext dc, String text, Font font, Size proposedSize, TextFormatFlags flags)
   at Infragistics.Win.DrawUtility.MeasureStringHelper(Graphics gr, String text, Font font, Size layoutArea, StringFormat stringFormat, Int32& charactersFitted, Int32& linesFilled, Boolean returnElementsFitted, GdiDrawStringFlags drawStringFlags)
   at Infragistics.Win.DrawUtility.MeasureString(Graphics gr, String text, Font font, Int32 width, StringFormat stringFormat, GdiDrawStringFlags drawStringFlags)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.MeasureString(AppearanceData& appearance, Font font, String stringToMeasure, Boolean isVertical, HotkeyPrefix hotkeyPrefix, ToolBase tool)
   at Infragistics.Win.UltraWinToolbars.ToolBase.MeasureString(AppearanceData& appearance, Font font, String stringToMeasure)
   at Infragistics.Win.UltraWinToolbars.ToolBase.GetTextSize()
   at Infragistics.Win.UltraWinToolbars.ButtonTool.CalculateLogicalSizeOfToolInstanceHelper(ToolBase tool)
   at Infragistics.Win.UltraWinToolbars.PopupToolBase.CalculateLogicalSizeOfToolInstance()
   at Infragistics.Win.UltraWinToolbars.ToolBase.CalculateLogicalSizeOfToolInstanceHelper()
   at Infragistics.Win.UltraWinToolbars.ToolBase.CalculateWidthResolved(Boolean useCalculateLogicalSize)
   at Infragistics.Win.UltraWinToolbars.ToolBase.get_WidthResolved()
   at Infragistics.Win.UltraWinToolbars.UltraToolbarBase.AdjustToolWidths(Int32 extent)
   at Infragistics.Win.UltraWinToolbars.DockRow.GetToolbarLogicalPositions(Int32 extent, Int32[]& widths)
   at Infragistics.Win.UltraWinToolbars.DockRow.CalculateMetrics()
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsDockArea.AddToolbar(UltraToolbarBase toolbar, Int32 row, Int32 col, Boolean refreshDockAreaSize, Boolean exclusiveOnRow)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsDockArea.AddToolbar(UltraToolbar toolbar, Boolean restoreOldPosition)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.AddToolbarToDockArea(UltraToolbar toolbar, Boolean restoreOldPosition)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.AddToolbarsToDockArea(List`1 toolbarList)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.AddToolbarsToDockArea(DockedPosition targetDockArea)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.InitializeDockAreaToolbars()
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.InternalSetActiveMdiChildManager(UltraToolbarsManager newActiveMdiChildManager, Boolean calledFromMdiChildActivate, Boolean remergeIfUnchanged)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.OnFormMdiChildActivated(Object sender, EventArgs e)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at System.Windows.Forms.Form.OnMdiChildActivate(EventArgs e)
   at System.Windows.Forms.Form.ActivateMdiChildInternal(Form form)
   at System.Windows.Forms.Form.WmMdiActivate(Message& m)
   at System.Windows.Forms.Form.WndProc(Message& m)
   at ?.?.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)

Is this a known bug, is there a hotfix?

Thanks