Brian,
I have had a similar trouble with my Abit BE6-II. Any HighPoint Drivers I installed for the HDD Controller crashed both Win98 and Win2k. I went even as far as cycling through all my components (CPU, Mem, Graphics, Modem, ECT) with other "Brand New" componets. No go. So I grabed another Motherboard (Asus P3B) and everything worked fine. I just recentley retried with there latest drivers and still get crashes and instability. I'd recomend either a New Motherboard if financialy possible, or disabling the controller.