So I had to install b6 back.

THIS PROBLEM IS IN FIREFOX 4 BETA 7

This happens, the folder doesn't open. Also nothing appears in extensions, themes, addons etc. I suppose it has something to do with Firefox 4 B 7 enabling even un-compatible addons...

http://img253.imageshack.us/img253/34.../firefoxfolder.png

Do you have that problem when running in the Firefox SafeMode?
http://support.mozilla.com/en-US/kb/Safe+Mode
Don't select anything right now, just use "Continue in SafeMode."

If not, see this:
http://support.mozilla.com/en-US/kb/troubleshooting+extensions+and+theme...

I do and I can't add folders or bookmarks.. And it's pretty hard to set a default theme when I have nothing in addons, extensions, appearance, plugins.

The problem seems to appear(bookmark problem) when I click a folder for the first time, it works perfectly but then when I move my cursor to other folder or just open a new one, it bugs.

Ok, even though you said don't select anything else right now, I selected the disable all addons and now it works perfectly, so when the Firefox 4 Beta 7 was installed it enabled all addons even the ones that aren't compatible with it and that is why I got the problem, maybe change that feature off in the .exe package?

Same problems here. Moreover passwords are gone and password manager doesn't work. Sync doesn't work (no account present) Addons list WAS empty (I fixed it restarting in safe mode, disabling every addon and starting it again) now it appears with all addons disabled (check for updates doesn't work though)

Where can I download beta 6 again?