I am having problems with USB debugging mode. When I connect to four different workstations via USB (two separate cables) whether or not in usb debugging mode , my prime does not show up in device manager. I was able to do this previously (a few weeks ago) and am not sure what would be causing this. I am not seeing any device in device manager either properly installed or indicating a driver issue. There are no indications that a physical connection is being made even though I can use a flash drive or other devices in the same usb port(s). Steps I have taken: 1) Tried multiple usb cables (2) 2) tried multiple computers (7, Vista, XP, Ubuntu) 3) connected u with dock and direct to tablet 4) reset the tf201 multiple times 5) reset the computers multiple times 6) reset the tf201 to factory settings and tried again 7) the device is not rooted and detects no newer firmware available 8) the device has no problem charging via either usb cable 9) tried mutiple usb ports on both computers 10) reinstalled my usb drivers 11) verified other devices work on the same usb ports that I tested with the prime 12) reapplied the 18.104.22.168 firmware (the latest as of now) 13) called Asus - not a lot of help but he called me "sir" more than anyone has ever done so in my life I have an RMA with Asus that I can do but I want to make sure I am not missing something critical before I send my prime back to asus-land for who-knows-how-long. Any help would be greatly appreciated! Thanks!