Hi Liquidnitrogen,
Thank you for your update.
Are you using multiple threads? The GridGroupingControl (like all Windows Forms controls) can only generally be assessed, and used from the thread that created it.
The GridGroupingControl does try to handle multiple threads by doing grid.InvokeRequired checks at the start of the ListChanged event handler and CurrencymanagerChanged event handler that have the code that the grid uses to respond to updates of the data from outside of the grid. But if you are directly calling grid methods from within your code and there is a chance the calls will not be on the thread that created the grid, then you should use grid.InvokeRequired checks from your code as well. If the grid.InvokeRequired comes back true, then you should use grid.Invoke (and not grid.BeginInvoke) to call the method again on the grid''''s thread. Here is a forum link discussing this idea.
http://www.syncfusion.com/support/kb/grid/Default.aspx?ToDo=view&questId=78If you do not think this is a threading issue, Please upload a sample showing the problem, we can debug it here.
Best regards,
Haneef