I have a strange problem with FF. It displays every webpage in the wrong way. No background colors are used - they are always white. Links are always blue, and tables have always a black border around it. FF also does not display an background images. I have no idea how this could happen. For me it seems, that FF uses for all webpages the same css (at least partially) and ignores the css shiped with the page.
Any hints? I could imagine that this problem could be trivially fixed but I do not know how.