Actually I did the memtest86 thing, it's pretty darn good eh?
I'm now up and running on a Via chipset motherboard, and an ATI 9200 video card.
Not a single crash, no more hassles, default XFREE86 4.4 support, the network card and sound card are up already by default, and I have to enable the usb mouse next.
I used to do Sun Unix admin as part of one job, and Slackware's thing is to "be more like sun unix" so I'm quite at home with where Slackware puts things.
Well, since I no longer own Nvidia hardware ( I took it back for a refund), so long folks, and hope your experiences are better than mine was with nvidia linux drivers!