Sat Nav showing wrong location...

[Smudge_si]

Hi

i have a mk 3 sat nav unit in my 02 x5 , the drive had recently crashed and left me with the blue "safe" mode screen . i have reinstalled the software and all is ok apart from i put the maps disc back in the unit and it wont find my position and when i manually add my location once i start driving it continues in a straight line in one direction . i am not sure where the gps reciever is or if i can replace it or even if that is the problem ?

thanks for any help
Si

[TerminatorX5]

does the screen show the coordinates? and, if it does, do they change as you move? does the system pick up any satellites? you can check that by going into service menu and look in the almanach for tracked satellites...