Lock-up after boot?

My system will boot Koppix fine with only one error during startup(about the i810 chipset-I have and i815). It gets all the way to into KDE (or iceWM it doesn't matter) and the system hard locks--Ctrl-Alt-Delt doesn't even work!
The CD works on other computers-I burned several and they all work elsewhere. It did work the first time I ran it, but now it won't.
I have reletively basic hardware Asus 815ep board, radeon 64M vivo [agp}, SB live value [pci 3] (with pnp off to detect), a 10/100 ovislink nic [pci 5], and a 10/100/1000 nec? nic [pci 1]. The modem/dsl is external. The set-up works OK with windows (same bios settings) There has to be some conflict in assigning IRQ/DMA that Knoppix can't handle--
Am I missing something in my BIOS setup, cards, etc?
thanks