rebooting

Got a strange problem with our 2007 W639 Vito - the cluster display has started 're-booting' (for want of a better description!) intermittently while driving. It goes blank, then displays 'no data', then comes back up with the miles/mpg/time/speed stats. all reset. I *think* the red SRS light on...

Just taken delivery of a 2008 SLK 55 AMG (September 08) and the comand unit has a habit of freezing and then rebooting when trying to set things up on it - particularly when connecting Blackberry or iPhone to it via bluetooth. From looking through this forum it does not appear that this is very...