Unfortunately, I can't remember the URL. I looked at my history, but I'm not sure.

I went to this web site, about audio, computer audio, CD players, because that what I was researching. Immediately a black transparent curtain slowly falls down over the screen and covers it. In the middle of the screen is a message that says something like: "Your computer is frozen. To restart, hit the power button" and the message appeared a few times directly underneath in a few different languages.

The site was right. Firefox froze and so did my Mac. I couldn't force-quit. I had to hit the power button on back of the Mac.

I was worried about a virus, so I installed Sophos and scanned the drive, but nothing was found.

Never saw anything like it.

You have had kernel panic. It probably has nothing to do with Firefox. For more information read Resolving Kernel Panics. Usually, KPs are related to hardware rather than software.

I have a friend who is also running 10.6.x with Firefox (also happens with Safari) and whenever he goes to a particular audio site (I think it is audion.com) he has a similar experience.

After a bit a trouble shooting the best that could be determined is that the site was throwing, via the browser, code that was "too new" for 10.6.x, which resulted in a kernel panic. May seem strange but everything else is working OK for him.

I did some research and a lot of troubleshooting. I've been looking for an excuse to erase my drive and start over, so I guess this is it.

I used Rember to check the RAM and it looks okay. I reset Firefox. All other test with Onxy were fine, though it took so long to try to fix permissions that after 10 minutes I had to force quit and use Disk Utility. Some interesting things with EtreCheck, regarding launch daemons and startup items. Turned out to be a more useful utility than I thought.

This help The XLab on kernel panics