1. Open the task manager and see what processes are being run while this is happen, pay special attention to the CPU Usage % to see how it spikes, then while that is going press the CPU tab so the highest % is up top, and that way you can see whats taking up all that processing speed. {Problem is your RAM/Processor}

2. Loading something up so there is no real problem with that just the program your loading. {Problem: Program Possible RAM issue}

3. Well I check some other sites about this problem and it could be the video portion of your motherboard could be failing and the only fix for that is to replace the motherboard, unless of course if you have a video card then try updating hte drivers or replace the card itself, after trying it on another machine.

4-5. Your hard drive is writing information in and if your not doing any saving of anything kind them you could have a virus in your computer

6. Is it repeating the sound or just sounds when an error shows up, and do you get an error pop up at all when this chimes in?

7. No idea since its hard to tell what script your running when you get that error

8. Usually you get that error when the Javascript doesn't load completely and so pressing stop the script usually helps or just reloading the page will fix this error. These errors usually don't cause to many problems though, because I get it a lot when I login into yahoo.

9. Go through steps 1-8 to troubleshoot your problem.

First off P4 processors have some issues with vista due to the fact that they are very old so you might have upgrade your processor, which also means upgrading your motherboard as well to go duo core. You don't mention RAM so I assume you have 2Gb needed to run it somewhat smoothly, and I haven't encountered any problems with vista from what your describing. I don't know any known viruses that are out right now, and so I would assume you are scanning to see if you picked anything up, and if not go into safe mode and scan your computers to see if they find anything. If I am reading this correctly your saying you have two firewalls installed on each computer, and if so thats a bit overkill and get rid of one of them since you got one through your router as well.

I think its just a memory problem and not a virus, and I would say do a little computer cleaning such as running disk cleaner and defragging your computer, maybe run spybot as well to fix some of the problems to see what happens.

PHEW...ON TOPIC

I put these tweaks in and seen some improvement, and someone of them are already defaults so that save some time, which lead me to find a few more on a topic I created for it as well. So hopefully when Firefox 3 goes full version that these tweaks will improve the memory even more.

That is one of the reasons I have sort of stopped liking firefox, I cant believe they let it do this. It gets really slow to the point were you have to restart firefox. =( its been giving me plenty of problems lately.

Macs aren't immune to this problem either. I'll have to try using those settings on my Mac and I'll get back to you all. Right now, FF is consuming more than 71% of the CPU!