This isn't obvious when using most printers, but using the
DesignJet with its large paper sizes makes it more clear what's happening.
We incorrectly validate the paper returned from the dialog against the device
capabilities values for margins using a DC from the original printer.
These impact the imageable area calculation
If the original printer can only handle small sizes, then the
reported bug is apparent.
Also we use to update that DC in a call to ResetDC() using a DEVMODE
returned by the page setup dialog.
Either we should prevent a user from being able to change the printer
at all from the page setup dialog, or, more likely I think,
we need to use a DC for the printer that's selected after we return.
We can get the selected printer from the returned devmode.hDevNames
and create a new DC for it .. its probably easiest to do this always,
although we could just do it in the event that the printer appears
to have changed.