...at least the problem of the SatNav not being available. I left the car (off) for a couple of h. So I assume one of those "cold re-boots" occured. I have noticed this myself, that if you leave the ignition off for a couple of minutes then the MK4 "powers off" so I guess this happened and the next time I switched the ignition on the MK4 came on again.

I'm going to try and re-burn my navigation DVD to a better brand disc to see if that helps with the "lock-ups"

When I used my original navigation DVD I didn't have any problems, or at least I didn't notice any, then, when I recorded a disc, the lock-ups started. However now, with v.31 SW, when I got my lock-up this morning, it seemed to corrupt the MK4 and a re-boot was neccessary.

Anyway, as mentioned, I'm going to try recording to a better disc on slow speed and if that improve anything