I found the tip yesterday reading somewhere and it works for sure now for me ; tried on a powered hub and it works too with vuescan and twain import from ps. did you tried a reinstall of scangear with the last version available on canon website ? Sorry that i can't help you for the moment but if...
with scanners canon 3200F on mac osX
I had excactly the same problem described above until I plugged the USB directly on the G5 instead of the hub on screen . works perfectly now with scangear . I've read that a powered hub would be ok too .
hope it will help
