I have my SYSON Smart Blue Mini BT GPS paired with my SMT-5600 and I use Mapopolis. I had issues getting the phone and GPS to "talk" occasionally. Sometimes it would work right away and sometimes I had to cycle the phone power. I have since done the following:
Set the GPS to use Com Port 6 on the phone
Under GPS Settings in Mapopolis, select Com Port 6 and set baud rate to 38400
Set Mapopolis to "Auto-Start GPS" when the program is turned on.
Now I turn my BT GPS on first, then I start Mapopolis from the the phone (GPS does not have to have acquired a fix to start, it just needs to be on). Also, I always leave blue-tooth running on my phone, if you don't, I would turn on bluetooth before you turn on the GPS and start the aplication. I haven't had any problems since. The first time it found the GPS, I had to enter the pairing code (0000) in. Now I never have to enter that or answer the question "A device is trying to connect, do you want to allow...."
if you can't get it figured out. They have forums over there, and one of them is dedicated to Mapopolis.
EDIT: With the "Auto-Start GPS" option selected, I get the "Com Port 6 is not available......." error when I start the program ONLY IF I have not turned on the GPS.