[robi-bobi]

hm, interesantno pitanje

ovo je za krajnje usere http://kb.mozillazine.org/Firefox_:_...all_Extensions
al kaze:

Uninstalling an extension might not completely remove all of the extension's data. For example, if you reinstall the extension, then you might find that it still uses its previous settings. There is no general way to remove all of an extension's data. See Resetting preferences for how to remove added preferences and restore the default preference values.

ili
mozda ovako:
http://kb.mozillazine.org/Adding_fil...uninstallation