Kcallahan Arkon do (or did) supply ones with built in GPS receivers as shown
here.
rpgsearcherz I don't know what else to suggest except follow the instructions in the user guide you sent me.
Perhaps you need to try setting the com port in the GPS function on the Axim.
Go start/settings/system/external GPS
If not there, try in Tomtom itself.
Without knowing how the mount you have works or the relevant settings in Tomtom, I can't be an more specific.