And here is another tidbit. When the GPS locks up with OpnCPN I close it. Then I open GPSinfo and hit start gps. Nothing happens. Then if I try to close GPSinfo it won't easily close. I have to hit the x icon several times and then the OS tells me that the program isn't responding and do I wish to close it. So I say yes.
So something is happening when the GPS locks up with OpnCPN that affects GPSinfo.
Keep in mind that you cannot use the GPSInfo and the OPnCPN at the same time. If you want to utilize both of the programs simultaneously, you can use a software called XPort. For more information on how to configure this, please click on the link: http://www.usglobalsat.com/forum/index.php?topic=1567.0
Also, can you set the buffers for the device's com port to 1? You can do this by going to your Device Manager and navigate to your Prolific Com Port. Right-click on it and select Properties. Go to Port Settings and press the Advanced button. Set the Receive and Transmit buffers to 1. Click OK and again.
One more thing, what is the firmware version of the device? In order to determine this, open up the GPSInfo utility. Select the proper com port and baud rate. Click on Start GPS. After a few seconds, press the Cold Start button. In the first few NMEA sentences, you should be able to see the version. It should look like something below: