Safari-SL and crumbled text

After upgrading to snow leopard some webpage’s text displayed (mostly in forms) doesn’t show up correctly. For example at…

http://www.joomlaportal.de/joomla-templates-und-design/193237-anpassung-des-css- menues-ja-erica.html

… Camino displays correctly, Safari does not. You may have a look at the difference here:

http://img15.imageshack.us/img15/5198/safari4camino.png

At another Mac-Forum I tried to post some text as code, and this is what Safari did:

http://img79.imageshack.us/img79/2102/mtncode.png

Again all three tested browsers, Camino, Firefox and Opera display correct.

'Crumbled' text like that I can see while writing into the form at another forum, too, so I have to use TextEdid first, than copy&past into the forum. Here it’s the other way round: I can’t see what I’m writing (text-field in the bottom), but after posting text (or even previewing) this appears correct („this is a test“):

http://img268.imageshack.us/img268/8966/atest.png

It doesn’t make any difference if I start Safari in 64- or 32-Bit-mode, if I use or do not use PlugIns like AdBlock or Cookies (I use to start in 32-Bit-mode in order to use this PlugIns).

If you have any ideas you’re really welcome! :o)

(Sorry for my bad english!)