Problems with extensions and themes in Firefox can often be overcome by making a new Profile. You might as well wait a bit before trying anything though. Version 1.0.3 of FF will be released shortly to overcome a recently discovered
security vulnerability. This version is still in the testing stage (although it does work ). I think it only took a couple of days to find a solution. The trouble is that, although the test version patches the hole, there has been work to do before official release of 1.0.3 is possible.
You can keep track of 1.0.3 progress and read the findings of the testers by following the links in the first post of
this page:
If you still get problems after this update, perhaps try making a new profile.