.... this helps:
got exactly the same prob.
difference between wm5.2/6.1:
you may need to manually configure a outgoing serial port for your bt-gprs connection as follows:
Select Your BT-GPS
check "Serial Port"
Now Your back to the BT-Device Menu:
Menu/Com Ports/Menu/New Outgoing Port/Select BT-GPS/Select Com"X"/Done
Now go to TomTom's GPS Settings an select your Com"X"
This should do.
devices need to be successfully paired first, of course