iTunes Resize Error AppleScript

Hey everyone!
I was just recently experimenting with resizing application windows with AppleScript. I picked iTunes as "Target" and wrote this:

tell application "iTunes"
set the bounds of window 1 to {0, 0, 1340, 800}
end tell

What happened was this:
In the other playlists, everything's allright, but it's a bit stupid that i can't search songs now and stuff...

I tried reinstalling iTunes, i tried to undo the script, but nothing changed, even with the Application reinstalled!
Does anybody have the same problem? Can anyone help me, because i'm quite at the end of my skills!

Thanks in advance,
Konki

PS: Please don't lynch me because of some mistakes I made. It's my first thread...