VDC system failure

2007 Alfa GT Q2

Had the car sideways the other night and the above message came up on the central display - along with the ASR and TC warning lights up on the dash... slowed down and tried the brakes - ABS still worked.

Stopped the car, engine off then back on - lights all off (as I had hoped) but then they came back on as i was driving in a straight line, at around 40-50mph.

after being left off over night the car seems to have been ok, but has on occasion repeated the messages - sometimes while driving spiritedly, sometimes while driving slowly and once while performing a 3point turn!

any ideas as to what it could be? my thoughts were ABS sensor, but ABS has remained operational throughout.
it had stood for the best part of a year... so wheels off and a scrub can't hurt - anywhere in particular should I be looking at?

ill get the toughbook charged up and hook the digs on I suppose... I just keep forgetting until it pops up again! its actually rather nice without TC - I don't think Alfa recalibrated it to take into account of the Q2 diff, which is a great bit of kit!