A couple of months or so ago, I had a revelatory web browsing experience. I had been using firefox 1.5 for what seems like forever, i briefly tried FF2 and found it to be a terrible resource hog, and quite unstable, so went back to the 1.5 which itself was quite a memory hog.
Anyway, I heard good news surrounding the release of Firefox 3 Betas, people were saying the runaway memory hogging issues had been finally fixed after all these years. I couldnt resist a download to try it out, as my pc is pretty limited in the memory department. I was really impressed, the version I downloaded was Firefox 3 beta 4, and it seemed to run like the wind, the memory usage seemed very stable, no matter how many tabs i opened, it was also much quicker at processing pages with lots of javascript in them. All was running swimmingly, then i heard that 3b5 had been released, so i gave it a whirl, but damn, it kept crashing on me all the time, so i went back to good old faithful 3b4.
Then just the other day, I started having strange problems, with 3b4 firefox was taking up loads of memory and thrashing the disk, at first i thought i might have caught a trojan horse or a virus, but various antivirus/spyware checks, turned up nothing. I decided to find out what was causing the disk thrashing, so i ran Filemon which is a nifty little utility for realtime monitoring of what files the pc is accessing. I found the culprit, Firefox was repeatedly accessing 2 files, urlclassifier.sqlite-journal and urlclassifier.sqlite and the files were ridiculously huge, one was 30 megs and the other 60 megs, no wonder my computer had crawled to a halt! Apparently these 2 files are used by the new security feature of Firefox, that can tell you whether the site you are visiting is genuine or has been blacklisted for hosting malware or phishing attacks. Theres 2 checkboxes in the security tab of the options panel that you can uncheck if you are having the same problem as me: “Tell me if the site im visiting is a suspected attack site” and “Tell me if the site im visiting is a forgery” Unchecking these options and restarting my browser, seemed to bring everything back to normal.
Its strange though, as i did a search on the web to see if anyone else was having this problem, and found that this was apparently happening as far back as the first beta of Firefox 3, so either the bug has popped back up again, or it hasnt been fully addressed. I hope the brilliant developers of Firefox, manage to get to the bottom of this one, as otherwise I am mightily impressed with how FF3 is coming along!
Have not tried out FF 3RC1 yet, as my previous experience of being on the bleeding edge wasnt a particularly pleasant one, I will wait a while, until things become more stable 