There are known issues with the USB driver built into Windows XP SP1 (Service Pack 1) that affect suspend, hibernation, and restarting. This issue potentially affects all USB devices and is not specific to those manufactured by Sealevel.
Microsoft released Hotfix 822603 to address this problem. If you are running Windows XP SP1, visit the link for information on downloading and installing the patch. If you are running Windows XP SP2 (Service Pack 2) or greater, you are already using the updated driver and do not need to install this patch.