Canoscan D1250U2F Scanner Problem

I'm very impressed with Windows 7 RC, but I have one inexplicable problem: my Canoscan D1250U2F scanner won't install. The peculiar thing is that it installed and ran with the Beta, but now the RC simply will not even acknowledge that the scanner is there. The system gives me a sound tone when I remove the cable and plug it back in, but no message box comes up. I have plenty of alternatives for scanner drivers, etc. but you can't install a USB scanner if the system can't see it. Again, it worked with the BETA!?