I have the new Microtek Scanmaker 5900 USB 2.0 scanner. It is hooked up to an Adaptec Duo Connect USB 2.0 / IEEE1394 interface card.
At random during a scan, the software will freeze and the scanner green light will flash on and off. Sometimes I can get round it by unplugging the USB cable from the scanner, delaying a few seconds and plugging back in. Other times, I have to reboot.
I am using Windows 2000 Pro SP3 on a dual processor system. I do have a Canon USB printer that works just fine when connected to the Adaptec PCI card, although the printer is not USB 2.0.
One point, if I plug the scanner into the USB 1.1 ports exposed by the motherboard, the scanner works perfectly, every time. And yes, my motherboard is an Intel OR840, using an Intel USB controller.
The only thing stopping me blaming the Adaptec PCI card, is the fact the printer works, although that is in USB 1.1 operation not USB 2.0.
Would appreciate any feedback.