My browser freezes up after 20-30 minutes and I have to reboot. This is now happening every time I get on the computer.
When I first open firefox it's pretty responsive. In about 10 minutes it starts slowing down. I'll click on something and it takes a long time to respond. In about 20-30 minutes it starts freezing up. If I move my mouse around it will sometimes respond, then it will just stop responding. When and if I X out I can't get firefox back until I reboot. However, if I go to Internet Explorer it works perfect.
Are you using ZoneAlarm for security?
If so, try disabling the ZoneAlarm extension in Tools > Addons > Extensions and see if that helps.