i've had a similar problem with mine except that it will not even start the update process. it shows "gathering information..." prompt as if it's going to begin and then sits idle. I tried letting it sit at first to see if it would begin and it ended up timing out overnight.
I too found that I can simply cancel the update, unplug the usb, and then immediately reattach the cable. I then works fine.
It doesn't bother me enough to call tech support. I chalked it up to another quirk in their software. If you have your USB attached to a powered hub, you might try attaching the cable directly to your computer's usb out to see if that helps the situation.