I have two problems which I think are linked.

Firstly I always leave the radio switched on and it goes off when I remove the ignition key but now for some unknown reason when I turn the ignition back on I have to manually turn the radio back on each time.

The other problem is that when I use the GPS to navigate it has stopped showing anythink on the display which is between the rev and speedo dials. Also when I go into the menu on the display there is now no mention of raido or navigation. It always used to show it so you could change the settings.

It appears the link between the radio/GPS and the display has broken.

Any suggestions please. I have checked all the fuses and they appear OK

Sounds like the radio is no longer talking to the CAN bus, You could try removing it and checking all the connections to the back of the radio. Otherwise you need to get someone to scan it with VCDS or take it to the dreaded stealers.

On second thoughts I believe there is a soft reset that can be performed, try a quick search on here for details of how to carry out the reset.