Cannot see column being dragged in RadGrid grouping drag and drop

[Niranjan]

I have a RadGrid built on lines of the demo - http://demos.telerik.com/aspnet-ajax/grid/examples/groupby/outlookstyle/defaultcs.aspx 
Grouping and ungrouping works when I drag and drop, but I am not able to see the column being dragged when I attempt to drag a column to and from the GroupPanel. 

Here are the relevant settings on my grid -

<telerik:RadGrid ID="MyGrid" OnItemCreated="MyGrid_ItemCreated"  Skin="MySkin" EnableEmbeddedSkins="false" GridLines="None"  
                                                OnNeedDataSource="MyGrid_NeedDataSource"  OnItemEvent="BudgetedChargesGrid_ItemEvent" OnItemDataBound="MyGrid_ItemDataBound"  
                                                 AllowMultiRowSelection="true" AllowMultiRowEdit="true" HorizontalAlign="Center" ShowStatusBar="false" AutoGenerateColumns="false" runat="server"
                                                 GroupingEnabled="true" ShowGroupPanel="true" ShowFooter="true"  EnableViewState="true" OnGroupsChanging="GroupsChanging" >
                                                <ClientSettings AllowColumnsReorder="false" AllowDragToGroup="true">
                                                    <Scrolling AllowScroll="True" UseStaticHeaders="true" ScrollHeight="200px" />
                                                     <Selecting AllowRowSelect="true" UseClientSelectColumnOnly="false" EnableDragToSelectRows="false" />                          
                                                     <Resizing  AllowColumnResize="false" ClipCellContentOnResize="false" />
                                                     <ClientEvents OnGridCreated="AnaquaGrid_GridCreated" />
                                                </ClientSettings>
                                                <PagerStyle Mode="NextPrevNumericAndAdvanced" AlwaysVisible="true" />
                                                <GroupingSettings RetainGroupFootersVisibility="true" ShowUnGroupButton="true"  />
                                                <MasterTableView DataKeyNames="InvoiceBudgetId" Width="100%" ShowGroupFooter="true"  FooterStyle-CssClass="smallText strong"  GroupHeaderItemStyle-CssClass="smallText strong"  ItemStyle-VerticalAlign="Top"
                                                 AlternatingItemStyle-VerticalAlign="Top" HeaderStyle-VerticalAlign="Top" HeaderStyle-HorizontalAlign="Left"
                                                CommandItemDisplay="None" Dir="LTR"  CurrentResetPageIndexAction="SetPageIndexToFirst" TableLayout="Auto" HierarchyLoadMode="Client" 
                                                EnableColumnsViewState="false" EditMode="InPlace" AllowNaturalSort="false" AllowCustomSorting="true" AllowPaging="true" AllowSorting="true" AllowCustomPaging="true" >
  <SortExpressions>                                                  
                                                </SortExpressions>
                                                   <Columns>
<!-- I have GridBound and GridTemplate Columns here--!>
  </Columns>                                           
                                                </MasterTableView>
                                            </telerik:RadGrid>

Is there a setting to turn this on or is this built in with the grouping functionality? If latter, what is suppressing that functionality for me?
Thanks,
NP

[Niranjan]

Update for the benefit of other members. I found a solution to this. The problem was at my end. The z-index of the container of the grid was more than the grid itself.

[Raffee]

This problem occurs when you have many layers on the page, some of which might override the default z-index of the grid CSS classes. the exact solution is to give the rgHeaderOver class a high z-index. e.g.:

 

.rgHeaderOver
        {
        z-index: 1200 !important;
        }