iPAQ logger problem (no G-record)

Perhaps some knowledgeable person can help me with this. I recently
started using an iPAQ with GPS_LOG WinCE interfaced to a Garmin II.
Before flying with it, I did a test run over the hills in my car; it
logged the trip perfectly and the log included the G-record. I then
flew with it and it logged the complete flight but without the
G-record. By viewing the .igc file with a text editor one can see that
the G-code was written to the test log but not in the flight log.
Perhaps I inadvertently changed a setting or failed to do something
that caused it not to write the G-record. I could not find anything in
the program's documentation on this subject. Thanks in advance to
anyone who can help.