I am having Firefox 3.6 and it keeps freezing and becoming non responsive. I have been forced to go back to IE7 with no problems. I would rather use Firefox. Why is Firefox freezing and becoming non responsive ? I have scanned my computer for all bugs and my computer is clean.I have even tried by disabling my add-ons for Firefox,upgrading to Firefox 3.6 Beta (revision 5) [3.6b5] downgrading to Firefox 3.5 and tried deleting my cookies and internet temp files and I have the same problem.
A lot of reasons can contribute to this. I have the experience with a old laptop with similar problem with FF. The reason found out to be with display card. For flash or simplar players, hardware acceleration is the default and if yours is a relatively old display card, say, prior to those able to do hardware decoding, FF hangs. Uncheck the box in the players if that is your case. In general these are caused by hardwares.
I used to have problems with Firefox sometimes freezing when starting or slow starting. After a little research I found that Firefox scans IE caches and this was the causing the problems. The problem was resolved by deleting IE browser history and temporary internet files on browser close. Not sure if this will resolve your problem but you can give it a shot. Internet options/General/Check box: Delete browser history on exit and Internet options/Advanced/Check box: Empty Temporary Internet Files folder when browser is closed