You appear to be running an insecure and unsupported Firefox version 4, if that is the case you should update Firefox. Also firebug is mentioned in your System Info aside, that may be something that possibly should not be left permanently enabled. Have a read of the article [[firefox crashes]] and try the troubleshooting tips and advice that article contains. Post back with how you get on. If crashes occur please paste into your next message a couple of the recent Crash IDs obtained by navigating to ''about:crashes''