Blaupunkt nx

I have a 57 mondeo with sat nav built in but have a couple of problems with it, the main on being that every time I start the car it changes all the settings on map to default so I have to change language to imperial, change map display to 3d which I prefer, and if I switch to map it shows germany until it finds sat connection, also does not save home or recent destinations. May be connected but also always comes on with radio and never remembers what was playing previously, does remember stored radio stations though. I have checked the fuse on the back of the unit and also any that I can find connected to stereo in fuse box and all are ok. I have tried updating tonthw lads at software but will not recognise the discs I have burned, have tried at least half a dozen, mixed CD and DVD burner on 2 different computers and from different download sources,it does read map disc no problem. Sorry for the long post buthyhought more info was better than not enough lol