Are you facing firefox browser's constantly lagging and not responding problem? After upgrading to newer version 5.0, i was facing that problem very often. When i try to open new tab, it automatically stops responding and does nothing for more than minute. I thought it's because of hyper threading, i tried to lower that and I have also tried clearing my cache and cookies. The problem was not in my computer, it was only on firefox browser. So i did know there is something wrong in firefox. Then i downgraded it to older version 3.6 but that problem was still there.