I have same problem with my xt Live.
I tried with other USB cables but not other PC. My PC is window 7 64 bit.
I downloded Monkey, Edit, Gearbox and Line 6 driver also. There is no driver can connect with my PC.
Gearbox has include driver but it still can't work. Somebody plz help and solve my problem.
It has been occured over 3 months.