Hi Had nothing but trouble with sp2 and my usb modem, and the VIA chipset. Under some circumstances the USB drivers do not update under sp2. To resolve this go into system via control panel and then onto device manager. Open up the usb tree and right click and select update driver on each entry in the usb tree, the drivers should update. I believe that sp2 effects the power the usb port can supply, especially such as a high powered device, such as a modem. If you experience the problem after updating the drivers, i think now the only way to go (until microsoft decide to put it right!) is to use a powered hub. Also there are ongoing issues with VIA chipsets and USB, check out the via support website for more info.