Challenger, I can't address your question directly, but I do have a related question/observation for you. First off, what board are you talking about?
I recently set up a CUSL2-C for a friend, along w/ a P!!!-866. I installed the Intel INF update, and that went fine. I then installed the latest ATA100 driver from Intel, and then the flakiness set in. End result was blue screens, caused by everything from putting in or taking out a CD from the DVD drive, firing up or shutting down Windows Explorer, and on and on. Oh, OS is Win98 Gold.
I wasn't far enough into it to matter, so I formatted the drive and started over, this time not installing the Intel ATA100 drivers. Guess what, not one blue screen. I enabled DMA in Device Mangler, and the system flies! In hindsight I recall reading something to the affect that the ATA100 driver is flakey on the CUSL2 series of boards.