It used to work nicely, now it won't even let me log into the blasted thing. "An error occurred, please go back to login screen," which is even worse than the previous unexplained "sync failed" error message.

Rather irritating as I can't find an alternate simple plug-in/extension that goes back and forth between FireFox and Chrome.

[EDIT - Added a few stars, the "fix" is to enable all cookies but 'tracking' cookies in Firefox]