Win2000 USB device drivers and S3 (Save to RAM)

Hello everyone,
We have tested several USB devices (a Belkin mouse, Belkin keyboard, VST
floppy drive, Logitec mouse, Cypress mouse) and noticed that all theses
devices function properly after an resume from S3, except for the Cypress
mouse!!!
The Cypress mouse is still listed in device manager, but required us to
unplug-plug the mouse to work again.

Does the USB device driver have to be ACPI compliant, supporting S3
transitions?
If so, what is the USB device driver required to do when entering and
resuming from S3?

Thanks!

Sammy Hui
Software Engineer
RadiSys Corporation