To revert back to NMEA mode, please follow the instructions below:
If you have an older version of the SiRFDemo, uninstall it and restart your computer.
(*Skip this step if you have the current one.)
Download and install this latest version (3.87): http://www.usglobalsat.com/store/downloads/SiRFDemo387.zip
Run the Sirf Demo software.
Connect your device, choose the correct COM port, and select the 4800 baud rate.
Go to Action > Open Data Source.
Next, go to Action > Switch to SiRF Protocol.
Then, go to Action > Switch to NMEA Protocol.
In the pop-up window, select the 4800 baud rate under the Baud Rate and click Send.
Close the Sirf Demo software.
Now, try testing your GPS Receiver with the GPSInfo program to see if the problem persists.