>Did you happen to try starting your Firefox profile over from scratch the way you did when you tried out Chrome?
I think you've hit upon one of the reasons to migrate from Firefox to Chrome.
I've been using Chrome for a couple of years now (I think it was shortly after they implemented extension support), and I've *never* had to mess about with my profile. With Firefox (and I've barely used it in a couple of years, so this might no longer be a problem) I had to clear my profile every now and then as upgrades tended to break things, especially in the presence of extensions.
With Chrome, I can install an addon and be pretty certain that it will continue to work, and it will automatically be installed and configured in exactly the same way on any other machine which I set to sync with my profile. In this sense, add-ons become as dependable as a core part of the browser, whereas the situation with Firefox is - to put it politely - less than pleasant.
IIUC this is a current area of improvement for Firefox, so hopefully by this time next year it should be solved - but why would I bother to switch back?
(FWIW I actually did jump through the hoops required to run an official Firefox build on Linux a few weeks back. Ignoring the fact that those hoops are not a minor issue, as I recall there were two reasons I decided it was inadequate:
One is that there's no config setting I can find to make FF on Linux and Windows behave in the same way; so far as I'm concerned if the button order in dialogue boxes switches depending on which computer I'm using at that moment, it's a massive usability fail.
The second reason was related to synching - I think it turned out that Firefox was capable of synching all the things I didn't care about, and few of the things I did, but I forget the specifics.)