Tom ... I have now tested that driver too, on both the XP and Vista machines. No change. At this point I'm really suspicious of that cable, from process of elimination alone it's just looking pretty guilty. I am HOPING the new one arrives tomorrow as having my bike dead is killing me.
I'm happy to try any ideas until then ... for my part, I'm out of them (I've been alternating between using 1.6.4 and 1.6.6).