Your addons look fine. Any idea when this problem first started? Did you also add Firefox to your exception rules in Comodo Internet Suite?

sill try exception rules but it works in comodo and windows so i need to do settings in networking maybe to let firefox communicate with the net? the minute i installed ubuntu u12.04 firefox would not open but everything else worked. i need someone to talk me through the process. but if too hard will just have to buy a new windows for an obsolete laptop