Hi Dave,
The nice things from "plug and play"
Windows sometimes incorrecly identyfy a GPS receiver as a "Microsoft Serial BallPoint". When it does it will install the incorrect drivers for it and your programs will do the wierest things.
Check in the Device manager for a 'BallPoint' thing. Can be on the serial ports, or eventually at the mouse settings. Disable or remove it. I think you have to reboot.