I installed 3.6.4 on XP June 23 and had much the same experience, except Firefox 3.6.4 never finished opening, even after nearly an hour, and brought my entire system to an excruciatingly slow crawl, even though pgm mgr showed FF getting 0% and system idle with 97-98. This happened twice with a reboot in between. Finally had to roll back to a previous restore point and all is fine now, except--no new version of Firefox. I'll wait to see more feedback about 3.6.4 before trying to install again.

I am having the same problem!

Mine is also slow after the update to 3.6.4. Very slow

I'm experiencing the same problem after the update.

Is anyone else opening Firefox and finding that entire screen is gray?

Firefox is very slow sometimes now(since the update), I have to use IE sometimes when pages just wont load.

I noticed at first that flash video was more slow and unresponsive after a firefox update, also that my laptop CPU fan was running much more than usual and CPU usage was relatively high.

In the release notes for this update it appears that there's now some kind of security wrapper around embedded objects, I've switched to another browser in the meantime (temporarily); hopefully the fault can be rectified.

Now using 3.6.6 and is slower than molasses. Loading takes forever if at all.

Firefox slow load - same problem - but once loaded runs OK; however, when I go offline and close it but come back about a hour later, same slow load, even tho I have set it to delete all cookies and temp pages on log-off.

I am having similar problems after upgrading to 3.6.7. My CPu usage spikes to 60-70% and everything slows to a crawl. I think I'll try restoring to a previous version or go back to using Chrome. Any suggestions would be appreciated.