I leave my pc running constantly (win2k pro). I never had this issue before, and it would run weeks at a time without rebooting. I noticed since I installed the latest version of avast (pro) that it becomes unresponsive when I come back to the pc after 4-5 hours of non use. I cannot do anything on the pc where avast is concerned.IE; access mail.It just hangs when I try to do that.I have to reboot pc and everything is fine again. I had AVG anti-spyware running on a trial basis, and I am wondering if there is any conflicts with avast. I shut avg anti-spyware down to see if the situation changes.