Tom Hemp wrote:
Turns out beta build 2416 contains a bug about reading .gpx files.
They know about this. It will supposedly get fixed in the next release.

or you can download GPSBabel 1.3.2 and copy/replace the EXE and DLL file
into the GE program folder.
This worked for me...

I had read about the bug that could be fixed by updating the GPSBabel
in Google Earth's directory, but that alone did not fix my issues. I
_think_ I remember that before I updated GPSBabel the kml file GE
created wasn't complete (just the structure with no actual data).
After updating GPSBabel the kml file was fine, but MapSource still
wouldn't automatically cause GE to start. Only after fixing the file
association did that start working again. Still no idea how the
association got messed up in the first place though.

Oh well, summary seems to be that you need to update GE's copy of
GPSBabel and make sure your file association is set right in Windows
for KML files.