Some Microsoft driver picked up my Varios USB ... and worked

[mockba_the_borg]

Yesterday I noticed there was a device o my computer called "My Roland Product", showing up as a MIDI port on MidiOx. When I sent notes to that port it turns out one of my Roland Varios with a VC-1 card on it emitted sound. So I went to the rack and indeed it has its USB led lit.
Me, being stupid, powered the device off then on again, and it was not detected anymore (came back to appear as a yellow triangle).
Now I am banging my head on the wall trying to replicate the "issue".
Has anyone seen this before?
Has anyone been able to make it happen consistently?
If I could use USB for midi consistently then this frees up two MIDI I/Os on my MIDI board.
If I show hidden devices on the device manager I see the "My Roland Product" there, but I am unable to re-associate that device to my Varios.
And if I right click on the Varios and try to make it use that driver manually, I cannot find the "My Roland Product" anywhere on the list of possible drivers installed on the computer.
I am going bananas with this. It it could happen once then it should happen again.

Any inputs are appreciated.