PostScript problem with Xerox Phaser 6280DN

[Steve Kleene]

What follows may not be a CUPS problem, but I think someone here will
understand it in any case.

I am trying to get CUPS working with a new Xerox Phaser 6280DN color laser
printer connected by USB.  The OS is Debian Lenny.  The PPD (from Xerox) is
installed as /etc/cups/ppd/Phaser_6280DN.ppd.  The printer definition at
http://localhost:631/ looks OK.  I can successfully print jobs from Linux
with a command such as this:

  lpr -P Phaser_6280DN test.pdf

However, if I print to the Phaser from acroread 8.1.7-0.1, the printout is a
page that is blank except for 5 lines of PostScript errors.  To investigate,
I used the "Print to File" feature of acroread.  I found that the file
created depends on whether the printer selected ("Name") is the old
laserjet_4_plus or the new Phaser_6280DN.  The PostScript file made for the
Phaser is very different, can't be viewed in gv (which uses the ghostscript
interpreter), and gives the error page if sent to the Phaser directly with
lpr.  The one made for the old Laserjet works in gv and prints OK when sent
via lpr.  Both PostScript files are LanguageLevel 3.  The one made for the
Phaser has an extra comment at the top:

%%TargetDevice: (Phaser 6280DN) (3017.104) 1

A similar line appears in /etc/cups/ppd/Phaser_6280DN.ppd:

*PSVersion: "(3017.104) 1"

Ultimately I'd like to be able to print from acroread.  Just what is
happening when I get the two different PostScript files?  When I invoke lpr
directly, does that bypass the Phaser PPD file?

Thanks.