I'm trying to create a route in mapper for a road trip I have planned.

I tried to use this script to generate a gpx file:
http://www.gnuite.com/cgi-bin/gpx.cgi

When I use this address:
17446 Pintail, Flint, TX 75762
it always gives me this:
Error: An error occurred while attempting to retrieve the driving directions - are the src and destination valid?

If you use that address in google maps, it gives two points and asks you to choose. Could this be the issue? If so, how do I get around it?