Rated 5 out of 5 stars

Today suddenly FireFox 6.0.2 on Mac OSX 10.6.8 had become the same problem...
Because I managed to solve it on a WinXP PC I tried my luck in OSX and it worked. :-)
In OSX you can find the needed file in:
\User (your name) \Library\Application support\FireFox\Profiles\RANDOM CODE HERE.default\Extentions\{582195F5-92E7-40a0-A127-DB71295901D7}.xpi

Further the solution is the same for Win and OSX.

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