I have problems with Ff showing flash videos. Flash player is version 11.4.402.278 (latest that I could find). The videos play without problems when having Firefox in "safe mode". I've tried to figure out if there is some of extensions that's causing the problem but any of extensions do this. I checked them one by one, without solution. So, only cause I can think of is the default theme of Firefox, because it is disabled in safe mode.

Tried also Flash 10.3, but it did nod work either. How can I test in normal mode, if it's the default theme that's causing the problem?