I know I’m beng a pesky user now, but the GPS software in general is so bad from a user perspective so your application really is better than alot of other things out there.
So see this post as love towards your app not something else… 
I’ve tried these combination:
Linux: USB (/dev/ttyUSB0) Bluetooth (/dev/rfcomm0 already connected with rfcomm bind 00:1b:C1:04:13:31)
Doesn’t work with your app but with gpsbabel
MacOSX Bluetooth
Doesn’t work with your app.
MacOSX USB
works very nicely…
**
Strange things**
First of all I think you application need to be split up in two parts, first is “log downloading” and the other is “device configuration”, it might help you organize the different settings and tabs a little more.
There really is no feedback that something went wrong neither on Linux nor MacOSX, you need to put some kind of feedback like “Couldn’t find bluetooth device, you can try to do this: bla bla bla”.
At the connect button I left the baudrate on 115200 and it still worked, I was under the impression that you needed to 38400 for the m241.
Output settings tab
Various what? “good color” “bad color”?
Advanced settings tab
First of I would say that the settings in tab one are very advanced, these actually seem simpler.
I’m guessing “Flash settings” Should say “Logging to Flash”.
There are lots of settings filled out in the “Flash settings”, many are set to one, e.g. GSA, but I know my m241 does not log those values.
The names are very hard to understand if you know nothing about NMEA, perhaps put some help in there?
GLL - Geographic Position, Latitude/Longitude
RMC - Recommended Minimum Specific GPS/TRANSIT Data <---- I have no idea what this means… 
VTG - Track Made Good and Ground Speed “How far you have traveled and current speed”
GGA - Global Positioning System Fix Data
GSA - GPS DOP and Active Satellites <— My interpretation of this is (which might very well be wrong): If these values are high your data is guarnteed to be bad, if low you data might be bad anyways. It only indicates how the sattelites are positioned and how that effects your position, you might still have radio interference that might mess things up.
ZDA - UTC Date/Time and Local Time Zone Offset (Log the timezone you have setup in the device)
GSV - GPS Satellites in View
Advanced Filesettings
What does this mean?
The set button*
There is a warning that says “this will brick your device please press abort”. Not a very useful button is it… 