I bought a Garmin 18x 5hz reciever to use for mapping. This is supposed to be WAAS enabled. A while back I asked about this model and someone said they had several in use.

Here's my issue, my position is not as accurate as WAAS should be. My GGA message says it has DGPS but it has a null space where the differential age and sat ID should be. I have set the reciever to use WAAS only. Has anyone used one of these recievers?

Here si a NMEA string
$GPGGA ........(coordinates).....,W, 2, 09, 1.0, 149.9, M, -31.7, M, , *64

As you can see before the checksum is the null differential age and ID, any ideas?