scrambled menu bar when quickviewing or app pop-ups open

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Highlight a file on your desktop
2. hit "space" bar
3. preview the document w/o opening and the menu bar goes wonky

What is the expected output? What do you see instead?
I didn't expect anything but the standard look but it scrambles and flashes. 
very annoying 

What version of the product are you using? On what operating system?
2.0 Mac OS 10.8.2

Please provide any additional information below.
Love it otherwise!

Original issue reported on code.google.com by [email protected] on 10 Oct 2012 at 3:19