Seen while testing the Beta 1 release. STR: 1. With Norton antivirus installed and running, open a Firefox browing session. 2. After some time, Firefox starts to consume system resources. Eventually I can't do anything on the machine. If I go into Task Manager, Firefox seems to be hogging all the CPU. I will have to go back to the machine and get an exact reading of what it is using, but the machine locks up so bad it is hard to do anything. Using the same machine, I did not see this running 2.0.0.9. It was only when I installed the beta that it started happening. Bia in #firefox confirms the same thing I was seeing on my machine, and reports everything was fine when he was using Firefox 2.0.0.9.

I have been reading a number of bug reports, and I realized that I had incorrectly reported Firefox b1 consuming CPU. What I really saw is similar to what others saw under general browsing conditions - suddenly FF would start consuming memory, and the entire system would become unresponsive. Tomorrow I will get better STR and add what sites I had open at the time, as well as dupe some of the other bugs that are reporting the same thing. http://www.lockergnome.com/blade/2007/11/20/firefox-3-beta-1-review-memory-usage-is-worse/ is one blog report that I saw that talks about memory usage.

Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9b2pre) Gecko/2007112005 Minefield/3.0b2pre I have seen the same thing in a profile with no active extension and never saw this before. Memory consumption rose to 509 MB and the whole system got unresponsive. It's interesting that this profile was startet with -no-remote and another profile (without -no-remote) which was running at the same time had no problems. The window was in background, so it took minutes to get the task manager and figure out the reason. No Norton stuff installed, but Sunbelt Kerio Personal Firewall and Avira Free AV.

I guess this is the same as/related to bug 404645. Turning off Phishing protection in the options seems to fix the bug for me.

The many writes to the anti-phising/malware DB could explain slowness with anti-virus programs installed (many do real-time protection that detects virus files being written to disk). Seems like that's going to be addressed somehow in bug 404645, so this is probably a dupe, or depends on that bug.

Marcia, OK to close, or dupe to bug 404645?