I'm not sure whether this is in the right category but anyway

Basically, I don't know what I did, but now most of the themes on ubuntu 12.10 look really buggy. Here is a screencast (recorded with gtk-recordmydesktop at 720p )

http://www.youtube.com/embed/QcnniIxGvoU

Please help asap as it's really annoying!

Thank you in advance