Yes.

I just tried it again (at work).
And everything worked.
Only difference ?

At home it was plugged into the car connector.
At the office it's connected to a ThinkPad brick via the (newly fitted) AC plug.

Could my connectore be broken and introduce interference ?!

The PC (my ThinkPad) and the cable are the same.
The software and the .upgrade are the same.

hmmm ... gotta try again back home...