C500 HELP PLEASE!

[Guest sportbilly2]

please could someone help me i have just purchased tom tom 5 for my c 500 with a fortuna clip on bluetooth gps receiver,the problem occurs when i have conected to the device, my phone will recognise it yet when i start the tom tom application up my phone loses the gps signal i.e. all traces of the fortuna gps device has disappeared from my bluetooth settings,my father has an older c500 but his will recognise the gps receiver and connect sraight away with no loss of device . i have a newer build phone to his does this make any difference please help!!!!!! [-o<