Since I updated FF to 3.0.9 (on Win XP), view source doesn't work. Even "firefox -safe-mode" crashes browser every time. Thank you
Mozilla Html Validator plugin! Hope 10.000 error reports I sent will help you.
update 27-04-2009: Yes, my friends were right. Html Validator plugin was causing this. After updating to v0.8.5.6 problem gone. And note to FireFox plugin developers - please DON'T put this in install.rdf without being completely sure that your plugin won't break anything (maybe 10% of plugins can do this):