So I'm seeing some weird behavior.
When ever the grid is navigatable and you are using the popup grid editing and user hits cancel, the grid scrolls to the bottom of the list. You can best see the bug when you choose to edit the first record. Additionally, after clicking cancel, then going to edit the first row again, the scrolling issue doesn't happen.
I've created a dojo to help display the issue: http://dojo.telerik.com/@email@example.com/aBUkA