Thanks for your reply,
We are using build 20100202, which I believe is the latest version.
The users reporting this problem are using firefox 3.6 with silverlight installed. (same problem in 3.5.7)
Browser cache has been cleared, so there should be no problem with our stylesheet.
I need to find out what differs between mine and our customers setup, which seems be be exactly the same.
If you have any ideas I'd appreciate to hear them.
Thanks anyway.
-Erlend