I have noticed when using Infragistics controls like WebGrid and Listbar. If you move the web splitter over the controls to hide a portion of them then the controls overflow the container. If you place these controls is div tags and set their position to relative and overflow to auto they will not overflow the entire container but will still overflow on to the websplitterbar. And any divs that are scrollable enabled they have very weird functionality. I do have a web splitter nested within a web splitter but I am just have some really weird functionality with the web splitter control.
I had a similar problem. I placed the ultrawebgrid in one of the splitterpanes that I have in my webdialogwindow.
When I enclosed my grid in a div and table tag, the issue went away. Hope this helps.
height: 100%;">
<table runat="server" cellpadding="0" cellspacing="0" style="width: 100%;">
<tr>
<td>
<igtbl:UltraWebGrid ID="UltraWebGrid1" OnPageIndexChanged="UltraWebGrid1_PageIndexChanged"
DisplayLayout-NoDataMessage="" OnSelectedRowsChange="UltraWebGrid1_SelectedRowsChange"
runat="server" OnInitializeLayout="UltraWebGrid1_InitializeLayout" Height="100%"
Width="100%">
<Bands>
<igtbl:UltraGridBand>
<AddNewRow View="NotSet" Visible="NotSet">
</AddNewRow>
<SelectedRowStyle BackColor="#CAD3E4" />
</igtbl:UltraGridBand>
</Bands>
<DisplayLayout Name="ctl00xUltraWebGrid1" RowHeightDefault="20px" StationaryMarginsOutlookGroupBy="True"
Version="3.00" BorderCollapseDefault="Separate" ColWidthDefault="" RowSizingDefault="Free"
SelectTypeRowDefault="Single" NoDataMessage="" AllowColSizingDefault="Free" AllowSortingDefault="OnClient"
HeaderClickActionDefault="SortMulti" ScrollBar="Never" TableLayout="Fixed">
<ActivationObject BorderWidth="" BorderColor="168, 167, 191">
</ActivationObject>
<RowStyleDefault BorderColor="#A8A7BF" BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana"
Font-Size="8pt" BackColor="Window">
<BorderDetails ColorLeft="Window" ColorTop="Window" />
<Padding Left="3px" />
</RowStyleDefault>
<FilterOptionsDefault DropDownRowCount="10" FilterUIType="HeaderIcons" AllowRowFiltering="OnServer">
<FilterHighlightRowStyle BackColor="#151C55" ForeColor="White">
</FilterHighlightRowStyle>
<FilterDropDownStyle BackColor="Lavender" BorderColor="Silver" BorderStyle="Solid"
BorderWidth="2px" CustomRules="overflow:auto;" Font-Names="Verdana,Arial,Helvetica,sans-serif"
Font-Size="11px" Width="250px" TextOverflow="Ellipsis">
<Padding Left="2px" />
</FilterDropDownStyle>
<FilterOperandDropDownStyle BackColor="White" BorderColor="Silver" BorderStyle="Solid"
BorderWidth="1px" CustomRules="overflow:auto;" Font-Names="Verdana,Arial,Helvetica,sans-serif"
Font-Size="11px">
</FilterOperandDropDownStyle>
</FilterOptionsDefault>
<HeaderStyleDefault BackColor="#E0E0E0" BorderStyle="Solid" ForeColor="Black" HorizontalAlign="Left">
<BorderDetails ColorLeft="White" ColorTop="White" WidthLeft="1px" WidthTop="1px" />
</HeaderStyleDefault>
<FrameStyle BorderStyle="Solid" Font-Names="Verdana" Font-Size="8pt" Width="100%"
BorderWidth="0px" BackColor="#E0E0E0" Height="100%">
</FrameStyle>
<FooterStyleDefault BackColor="LightGray" BorderStyle="Solid" BorderWidth="1px">
</FooterStyleDefault>
<AddNewBox>
<BoxStyle BackColor="LightGray" BorderStyle="Solid" BorderWidth="1px">
</BoxStyle>
</AddNewBox>
<SelectedRowStyleDefault BackColor="#B7B6CA">
</SelectedRowStyleDefault>
<EditCellStyleDefault BorderStyle="None" BorderWidth="0px">
</EditCellStyleDefault>
<Pager PagerAppearance="Top" PageSize="25" QuickPages="10" StyleMode="PrevNext" AllowPaging="True"
MinimumPagesForDisplay="2">
<PagerStyle BackColor="Gainsboro" BorderStyle="Solid" BorderWidth="1px">
<Padding Right="20px" />
</PagerStyle>
</Pager>
<RowSelectorStyleDefault Cursor="Default" Font-Underline="True">
</RowSelectorStyleDefault>
</DisplayLayout>
</igtbl:UltraWebGrid>
</td>
</tr>
</table>
</div>
I had a similar problem. The DIV and table didn't do much for my situation.
I added this style to a treeview control and it then worked
style="position:absolute;height:100%;width:100%;overflow:auto;"
The scrollbars and the controls inside the splitter pane would spill out over their parent until I set the position to absolute.