When I'm using Firefox for Windows XP and only Firefox (both version 3.6 and version 4) - I am consistently getting a message from my Symantec anti-virus that a denial of service is logged from IP address 68.87.76.182 - and ultimately after I get this message; Firefox freezes up or actually loses connection to the internet and cannot find any webpage. I'm forced to not only close Firefox, but I actually have to CTRL+ALT+DEL and cancel it under the processes tab before I can re-open. A full virus scan using Symantec finds no virus - scanning also using Spybot and Malwarebytes Anti-Malware finds nothing - my computer appears to be free of virus or spyware issues. I am NOT having a problem using IE - but unfortunately I have to use a very old version of IE for company purposes - so Firefox has been my preferred browser until now that it's not working properly - any ideas?