Unusable stretched dialog content windows

I’m seeing really wonky stretched dialogs that are unusable - these seem to be restricted to when a dialog’s content changes, like when you change to import different mesh types. See attached video below. I’m on a Mac Pro 2013 with FirePro D700.

http://dl.dropbox.com/u/7990437/wonky_display.mov

more:

http://dl.dropbox.com/u/7990437/more%20glitches.mov