Finally I got it working with my Bluetooth Receiver Bt-338 using bluetooth com port 7.
I went to Tomtom support site and downloaded upgrade version
5.10 and
5.21 and installed both in the right sequence. Now everything works perfectly.
Axim X50v Windows Mobile 2003
1GB SanDisk SD card
Tomtom 5.21
GlobalSat BT-338