Can't use extensions or Themes in Firefox

Or rather can't open and install them.
Yesterday I installed latest windows nightly after I uninstalled 1.0.3 (deleted all files from FF folder before install). So when I wanted to install extensions (mouse gestures, dictionary search and so on)

Thing is when I try to install any extension I get download window, but it don't know what program to use to open the extension with Sad Same thing with Themes. I fixed the extension stuff with downloading them to a desktop and than draging them on to the FF window (they install that way) but I can't get themes to work Sad So I I tried to tell firefox to open files with firefox Razz (Open with , than Browse and find Firefox.exe) but it didn't help.

So I guess somehow extension handling got borked Sad
Any chance of fixing this somehow? (already tried uninstalling and reinstalling and such and no go)

Thank you for your time!

What is the message you are getting? Is it saying it can't install because of your browser version. There is a work around for this. In your browser window type about:config and it will open up a window. Scroll down to where it says app.extensions.version and change it to .8 or .9 so that basically tricks your browser into thinking it is firefox .9 or .8 instead of 1.0.3 so the extensions install.

Mozilla had to disable the themes due to security issues which are supposed to be addressed with the 1.0.4 release. Somehow the flaw allows remote access through tricking the user into thinking they are installing something from the Mozilla site but instead are being directed to a bad site to install malicious content.