Vista - problems printing to a file in Vista

I have set up a generic postscript printer by using the generic
postscript printer driver and then checking FILE: Print to File in the
Ports part of the printer properties.

When doing this in all previous windows systems, when printing to this
"printer", a file requester would pop up asking me to type in a file
name, and then the printer job would appear as a postscript file saved
to the hard drive.

In Vista, I have never been able to make this work. After I type in the
file name and press return, an error box pops up (title in the titlebar
reads Local Port) with the following message:

Could not open the file: Access is denied.

I'm assuming this has something to do with UAC. But short of turning it
off, surely this must be a way to print to a file. But, nothing I try
seems to work. Any ideas?

Thanks,

Howard