I've tried unplugging the cable, swapping USB ports, rebooting XZU. The device won't mount as a mass storage device in CWM. Rebooting Windows is the only thing I've tried that fixes the issue but it happens again. So I gather it could be a Windows issue although I haven't changed anything on my Windows installation that I recall. I have however been flashing various firmwares onto my phone. ATM I'm using stock firmware and I *think* the issue has only happened with the stock firmware.
Edit: Now it's still happening when I reboot Windows :|
Can anyone suggest anything to try to fix this annoying problem?