Hey, WOW! Now it works great! Thank you very much!
I first tried the nightly snapshot so that I'm now using 1.0alpha1. Hope that doen't matter. But that version also didn't help me. Same bug as before. Then I fetched the new images.inc.php from berliOS and now it works. Thanks!

You're right, I'm using Safari! Never had a problem like this with Safari.
I tried it with Netscape and it worked... With Firefox also no problem!