Firefox mini-freeze

Question

Hardware is quite strong for browsing Intel Q6600, 4GB RAM, Geforce 8800GTS 512 MB
I am experiencing mini-freezes, also I have to mention that I use a 24' screen at 1920x1200 and I browse most of the sites zoomed in (realy like the way it is implemented in firefox):
These random (i cant locate a pattern) mini-freezes (some times -5%- after the pause i hear the HDD spinning) happen when:
1) I type (i originally thought that this happens because I have a spelling addon)
2) I see videos on youtube: problems include minifreezes, reduced performance (cant watch 1080p), minifreezes seem to affect caching which stops and i have to point the slider to a new location to re-initiate.
Have checked with Internet explorer and Opera and those problems do not happen, performance is better and there are no minifreezes.

Answer 1

I had this problem- mini freezes on videos (Flash)- at first it was just short jumps when I went to full screen, however today it seemed to affect even the shrunken video. Trying all the suggestions in this thread did not help. All plugins were updated to most recent version. Firefox latest version 3.6.12. Safe Mode did not cure it. Turning off different plugins did not cure it. Trying earlier versions of 3.6 did not cure it.
Curiously, if I had a tab open using IE the Firefox tab would actually work a bit better....instead of mini freezes, some erratic jumping of the frames in the video. And the tab using IE would render the video perfectly, whether small or full screen. It appeared to me to be something inherent in 3.6 causing the problem rather than any particular add-on. In utter frustration I dumped 3.6.12 and went back to 3.5.14 and once again all is well. No more video mini freezes. Until this is fixed I have no intention of using any version of 3.6 And nothing could persuade me to try 4.0 Beta. I'll stay with this old 3.5 until Mozilla is certain they have fixed the problem or can tell us how to do so.