Complex issue with m50 editor and cubase

[TerenceWatts]

Background: Windows 7, Cubase 6, Korg M50/73 all working fine.
Hard drive failure; new drive; clean installation of Windows 7, Korg and Cubase 6

Problem:

1. When running the editor in Cubase, SEQ mode allows changes of voice on the virtual keyboard in the editor but the physical keyboard still keeps the same voice. It is also low volume, while the virtual keyboard is ok.

2. Changing to PROG mode instantly restores volume to normal and the physical keyboard plays the last voice that was selected in SEQ mode (even though it would not previously play on the physical keyboard!)

3. Running the editor without Cubase works perfectly, virtual and physical keyboard playing the same voice(s)

4. Seeking to load a previous composition from the old set up causes a freeze necessitating a forced restart of the PC.

Already tried: Uninstalling both Cubase and Korg, then reinstalling after restart - everything is still the same afterwards.

I would REALLY appreciate any ideas at all - I've already spent hours trying to sort this one out!

I hope there's somebody clever 'out there'...

Terence