Net Use LPT1 : The Network Location Cannot Be Reached

I am trying to capture LPT1 for use with a generic printer driver that runs on a port that creates a text file.

Here are the steps I use:

- Add a Generic Text Printer

- Create a new Local Port for the printer and name it C:\temp\PrintThis.txt (as an example)

- Share the Printer with the share name GenericT

Then I use Net Use to capture LPT1 to the shared generic printer like this:

       Net Use LPT1 \\machinename\GenericT /persistent:yes

This works fine as long as the machine is connected to ANY sort of network connection. I can connect a cable to a DSL modem and it will work but if the cable is disconnected I get the following error:

       System Error 1231 has occurred

       The network location cannot be reached. For information on network trouble shooting see Windows Help.

Any thoughts?