Hi. I just updated to the latest internal build for Silverlight RadGrid, since this release should have the bug with the UI not being updated on recalculation. This seems to work fine until I add a ResultFormatString to the SumFunction, then the display of the sum gets messed up. Can you confirm if this is a bug in the component? I have attached the code I use and a image of how it looks when messed up.
I also tried using a IValueConverter on the binding on the TextBlock, instead of the ResultFormatString, with the same result.