I have connected a Garmin GPS to my USB sound card and setup the configuration to use "GPS time" and the mode is "GPS sync without NMEA".
The setup works correctly but the clock display the seconds to two decimal places, ie 2012-11-07 04:34:16.00
If I then set the mode to "GPS sync w/NMEA decoder" the position display appears correctly in the GPS setup but I get an error message "Timestamp didn't pass plausibility check!" and the program defaults to computer time.
I suspect the second display to two decimal places is causing the error.