firefox using 100% cpu
I'm running firefox 11 on Win 7 Ultimate. For the last 2 weeks it is pegging out the cpu at 100% and this is with 3 tabs open. I close it and check the task manager it stays open. I have to end the process. I then reopen and all is good. It will work for a while but flash constantly crashes in youtube (not saying that is a firefox problem) but I don't get this cpu usage. Using 600 MB RAM and 100% cpu with 3 tab...come on now. So, any ideas what is going on?