The following patch adds support for rfcomm to maemo-mapper. One of the goals of the patch was a minimal number of changes. Clearly the reuse of the first character of _rcvr_mac as an indicator of the type of connection is a hack. It's more reasonable to set a state variable _rcvr_conn to one of:
depending on whether _rcvr_mac has 1) colons, 2) slashes, or 3) dots in it respectively.

That said, it works. Instead of a mac address in the Settings...GPS/MAC, you use /dev/rfcomm0 or /dev/rfcomm1, or whatever. No more mysterious bluetooth silence.

http://russnelson.com/maemo-mapper-0.2.3-rfcomm.patch