Well, I'll have a go with a farkle set, though I've no idea which bit I'm supposed to be jiggling!
Just wondering whether in this instance the lock has gone. As I recall, there was always a bit of resistance to the lock but its not there now. Maybe that's just connected with the jamming however.
Hey, that looks a really useful thread, thank you.
I don't recall doing anything out of the ordinary when I last put the nav in the cradle. Again, something I note from the vid on the thread you shared is that apparent slight resistance you should get when you turn the key - I'm sure mine used to be like that but isn't now. And no, haven't left the bike unattended over the period since the Nav last went on, so it's not a case of somebody fiddling with it.
I'll take a look - I'm not the best at these things, and if it looks like I might make it worse then off to the dealers I guess. Problem on that front is that my extended warranty is carrying a 250 quid excess!