The only Windows family is supported currently. I have only a slow WinXP machine so can't run the extension under other OS.
Workarounds. I'm sorry it's needed to use them sometimes but it helps at least and the bad situations happens rarely if your Firefox is always on the run.
1) If status bar contains just frozen text then try to restart Firefox once or two.
2) If the tray got shifted you can drag it to the right place manually or restore/maximize the Firefox's window so the tray gonna move back.