FIrefox freezing up on Youtubes

Had Firefox 3.0.11, inconsistently freezing up while watching youtube (sometimes after a couple of minutes, sometimes after half an hour). Upgraded to 3.5, same. Deleted then reinstalled latest Flash player, same.
Running XP pro SP3 w/ 3 GB RAM , Geforce 8500, plenty of drive space. Only 2 tabs open... Couldn't find any conclusive fix on mozilla's site or adobe... Any ideas really appreciated! Hate to use IE....

 

There are many possibilities according to a YouTube Help search I did. Skim through and see if anything might work. If all else fails use Opera, which doesn't seem to be affected by the problem.

 

Download speed that is somewhat slow will also cause this, possibly not browser related at all. ed

 

Apparently it's not only Flash related... Skype frezing up too (without video)...
Updated nvidia drivers and NIC drivers...

 

Getting over 9Mb download speed and about the same upload..

 

Run FF in safe mode (from the Windows Start menu) to rule out a add-on problem.

 

I gave up, picked up another SATA drive, reloaded XP and am trying to put everything back together... Windows XP repair hung 5 times on 34% loading drivers and I finally gave up. Fortunately can still access files from the old drive.... Haven't quite gotten to the point to verify if my original problem doesn't exist..