The MSI driver link I provided is for the new Intel 845 chipset. The BIOS message amy or may not apply to other motherboards and I certainly don't know how this applies to your Abit motherboard. It may not be needed, then again it may be critical.
I know one thing for sure about Windows, if the drivers you are using are not correct or complete (which is the case here) you can't expect 100% performance and compatability.
Additionally, the HP 4100 isn't the most forgiving device from a USB stand point. I've seen this model fail in many different misconfigurements. Right now you're system is not properly configured.
Bottom line: You can try the MSI drivers and risk a reinstall or you can wait until Abit provides the correct drivers and BIOS (if necessary).
The question seems to be: How badly do you need that scanner?

Jeff Roberts
USBMan

: : MSI uses the same VIA USB 2.0 controllers that Abit does. No harm can come to your PC - it can only help. You can always roll back the drivers if they don't.

: : You say that the scanner is plugged into the onboard USB 2.0 ports. Did you connect the rear USB 2.0 connector and plug there, or did you plug in up by the PS/2 ports. Those high ports are the "good" old VIA 1.1 controller and may require tweaking to get them to work properly.

: : Bill

: The Abit board I have has an INTEL-based USB chip, not one from VIA. The board is based on the I845E chipset. And yes, I tried connecting the scanner to the "standard" UCB ports on the motherboard, as opposed to the ones connected via the extra header-- no difference. From the documentation for the motherboard, they are ALL usb 2.0 ports, not 1.1.