I replaced the RCD510 with a RNS510 and since fitting I'm finding that if I've been listening to music through the iPod connected to the MDI, the next time I get in the car the source on the RNS unit has switched back to radio as the source. However this isn't happening all the time, as sometimes from getting out the car in the morning and leaving it all day whilst at work, MDI will still be the selected source, but other times leaving the car for 15 minutes will switch it back to radio.
This has happened on a couple of units as I wanted to test whether the RNS was faulty, so I'm suspecting it could be a coding issue - assuming it's not a "feature" of the RNS510.
Are other people seeing the same thing with the RNS unit?