Ecco il log:

zaltar@darkstar:~$ firefox
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
*** loading the extensions datasource
(...)


@eddis:
Ho installato firefox servendomi dell'installer ufficiale.

Nota:
L'installazione di firefox, almeno in apparenza, risulta funzionante per root, al contrario non funziona per user.