"Print to file" and UNI driver

Hi,

I'm developing a printer driver based on the UNI driver example of the DDK.
Currently, it is not working very well when the "Print to file" option on the
print dialog is checked.

From my understanding, the driver should be receiving the raw printer data
through the COemUni2::WritePrinter() function. Right now, this function only
gets called right after GetImplementedMethod() queries for WritePrinter.
WritePrinter returns S_OK, but it is never called again.

Am I missing something about this process or am I completely off base on how
to get the "Print to file" option to work?

Thanks!