DDJ-RZ controls stopped working, audio ok

This is pretty much the same as a problem I had before with the RZ. All the controls (jogs, buttons, knobs) stopped working on the PC connected to USB A, although the audio was working perfectly as were the meters. The PC connected to USB B was still working for both controls and audio. I unplugged the USB connector from USB A, plugged it back in again and things started to work again. I didn't restart the rekordbox software.

Not sure if this is a logged issue as it was reported before, but it's something that should really be looked at.

Windows 8.1 with all updates, latest rekordbox & drivers, i7 + 12G memory

Mike