Files opening behind finder window instead of in front

Whenever I open a file/photo, it opens behind the current finder window instead of in front like it's supposed to.. I recently reinstalled leopard and I think that could be the cause of this problem.. Does anyone have have a fix? if not I'll just call applecare... Thanks
Someone else is also having the same issue:
http://discussions.apple.com/thread.jspa?messageID=7071307

I'm having the same problem

mac OS 10.5.5

EDIT: Also for some reason, txt files will open in front and NOT behind