By your description, I think your belief is correct that "it's a bug in how GPS data is transmitted to the applications." It sounds like the GPSD server (which is responsible for collecting data from the receiver and distributing it to registered listeners) is having trouble getting the data from your receiver. Older version of Maemo Mapper (prior to v2.1) allowed you to interface directly with a bluetooth receiver (bypassing GPSD), because GPSD was not common to the 770 and N800. The problem with this is that only one application can directly access a bluetooth receiver at once. Since v2.1, Maemo Mapper uses the new libgpsmgr framework, which uses GPSD exclusively, allowing other applications (like the built-in map application) to share the GPS data with Maemo Mapper. Try using Maemo Mapper v2.0.5 and making sure that the "gpsd" program is not running in the background. (You can use "ps | grep gpsd" from the command line to check if it's running.) I think you have to disable all the GPS stuff in OS2008's control panel in order for gpsd to be disabled.