I'll try it again, I removed everything from Safari the first time. I'll edit this when I tried it.
Well, that didn't work ... So I tried restoring my original theme (I was using AlumiteX from Aquaworld with Themer Anche) Now everything works ... The only problem is that I'm not too fond of the original Aqua I changed the Theme again, now to sth else, Tabs didn't work anymore, once again the spinning wheel of death. Damn ... So Tabs don't work for me while I'm using themes Snif
I take it when you trashed everything Safari you also trashed Safari? Give that a shot as well. Get rid of all Safari-related stuff and re-install Safari.
Good luck
[edit] Erm... ooh. Yeah I think I remember seeing something about Themes and Safari yesterday over at MacFixit. Hopefully this will get straightened out shortly.