Admin panel align problem

The admin panel of my installation is getting messed up.

See this examples:
http://img.skitch.com/20100204-dwkra48hxq8sbmrm3x51rj1nym.jpg
http://img.skitch.com/20100204-jfukdiep3b3p52xtjbtkyp9pwn.jpg

Does anybody know how this is happening? It's quite annoying when adding a image to a post.