I've had my Macbook pro 15" for about 3 years... one thing i'm fully aware of is that I need to replace the battery. In the meantime I have it running on AC power 100% of the time. It still starts up and is ready to run in less than a minute, but constantly is freezing up when i'm browsing the internet... on the simplest of html sites with minimal bandwidth usage. Usually i'll get the little swirling rainbow colored "loading" icon and thats the signal to restart... sometimes i'll just lose the mouse pointer all together and the comp is frozen. It does freeze occasionally off the internet as well but not nearly as much... most of my time on here is spent on safari, and i've downloaded all the necessary automatic updates. I can't take it anymore! I know the battery needs to be replaced but since it's running on AC power it should be fine right? I can't imagine that would be causing the constant freezing. Looking for help, please!!?