This problem is now SOLVED.
Thanks to those involved!
I thought I should check out Scribus so I installed version1.1.2-2 from the unstable branch in Debian.
When I start Scribus it shows the splash and the opens the program.
Lo and behold! No text on the menus?!.
When I click on the icon for 'new' a dialog window appears where I seem to be able to make some choices, but no text here either...
Starting Scribus from a terminal doesn't give any extra output at all.
The only dependency apt-get complained about was python-2.2. so I installed that together with Scribus.
I did a search on google and in some forums but couldn't find anyone with a simular problem.
Some people seemed to have som problems with qt so I checked that I had the environment variables:
...but with or without them, the problem is still there.
Out of curiosity I tried running Scribus as root and it worked flawlessly.
Could this be a permission problem..? I don't know where to start looking, since all my other programs work perfectly.
Does anyone have any tips?