I'm writing a "small" task management software for the team I work for. Obviously I'm using the great features of WPF and the current version of the WpfToolkit:DataGrid

Now, have a look at these two pictures:

problem1.png problem2.png

The only difference from (1) to (2) is, that i scrolled maybe 5px down...

I have SnapsToDevicePixels activated for the whole application, and it looks like this has some rounding errors sometime... If you didn't see it, I'm using an DropShadowEffect the show the currently selected item, and as I wrote previously This DISABLES SnapsToDevicePixels. But interestingly I can't see a difference in text rendering in the good case...

Do you have any ideas why this happens?