I actually didn't have to do anything, the car was left (off) for a couple of h and I just went in and started the ignition and it all came back into life...

Thanks for the reply! That would probably be quicker...

I used to have these resets and lock-ups before on v.29.1, but I thought that upgrading to SW v.31 would perhaps sort that, but I guess not, my next guess is that the 2008.1 DVD navigation disc that I'm using (burned) is perhaps defect, I'll re-burn it, perhaps this time on a slower speed and I'll use a better brand and c...

Thanks again!