gpsd seems to be broken when talking to a BU303 GPS device. If the BU303 is put into NMEA mode, gpsd will think it sees SIRF data from it. When this happens, it will change its mode to SIRF which the triggers then BU303 to really go into SIRF. The BU303 is unreliable enough as it is.
This is bad for me, as my Navigator software needs raw access to the device in NMEA mode and doesn't know how to switch it back over.
The answer is compile gpsd from source without SIRF support:
./configure --disable-sirf
(As an aside, I would really like to write a 'fake' serial device which feeds data from gpsd as raw NMEA. That way I wouldn't need to have scripting which kills gpsd (and thus my tracking system) when I want to load Navigator 4).
