Every once in a while when writing to the hard drive my Slackware 9.0 system freezes completely (the NUM and CAPS Lock keys are flashing - Why?). Most times I've been downloading small files from my ftp, but at high speeds, ~100 MBit/s when it happens. It has also happened while starting large programs like opera and konqueror and when I think about it also while downloading files at low speeds from internet, at around 50 KBit/s.

I also experienced freezes like this when I was using an old Slackware current (~three months old by know) and the Slackware 9.0 rc-1. But before that, when I used Slackware 8.1, nothing like this ever happened. Actually, I never experienced one single crash or freeze while using 8.1. So, the problem has something to do with something added after that, if that's to any help.

Oh, one more thing. It's only in X these freezes occur. Not even while compiling large programs like winex (which include much disk writing) while not running X, the system freeze (but I did once when X was running). That makes it a little doubtful to think it has with disk writing to do, not besides that it always have happened when the hard drive have been under heavy pressure in combination with X running I have no clue.

Is there ant other problem with these symptom? If so, please tell me about it.

In your system BIOS you might want to disable system and video bios caching and retest.

Like I thought, those options are not visible in my prehistoric BIOS. However, since I didn't have this problem when running Slackware 8.1 on the exactly same hardware, the problem ought to have something to do with the newer versions of Slackware, right?