When hitting the OK button, I get a dialog with "Failed to save preferences file. Any preference change will be lost at the end of this session." firefox-0.10.0-1.0PR1.0
Probably related: Firefox does not save any new bookmarks. Also, confirming bug.
*** Bug 133673 has been marked as a duplicate of this bug. ***
*** Bug 133706 has been marked as a duplicate of this bug. ***
You can work around this by making a new profile or by deleting a lot of the components of your existing profile (I believe it's actually one of the db or the dat files that is the problem).
Fixed in firefox-0.10.0-1.0PR1.1 which should be available tomorrow morning.
I am using "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0", and I'm getting this problem.
Same symptoms with Firefox 1.0.1. Bookmarks and preferences are only saved for curent session. Defaults when restarted