ps problem

[Gary Aitken]

I'm trying to debug a duplex printing issue with my printer.
I've got cups installed.
The following file, when printed with 
  lpr filename.ps
goes through the duplexing motions, but never prints anything.
Not being much of a ps geek... hints?

%!PS-Adobe-3.0
%cupsJobTicket: media=Letter sides=two-sided-long-edge
%%BoundingBox: 36 36 576 756
%%Pages: 2
%%LanguageLevel: 2
% This file has two pages, with the second supposed to be printed back to back in proper orientation;
% i.e. not upside down.
%%Requirements: duplex
%%DocumentNeededResources: font Times-Roman
%%EndComments

%%BeginDefaults
%%PageOrientation: Portrait
1.0 setgray
/Times-Roman findfont
60 scalefont
setfont
%%EndDefaults

%%BeginSetup
%%BeginFeature: *Duplex DuplexNoTumble
<< /Duplex true /Tumble false >> setpagedevice
%%EndFeature
%%EndSetup

%%Page: (Front Page (1)) 1
% Page 1 text
1.0 setgray
/Times-Roman findfont
60 scalefont
setfont
newpath
100 200 moveto
(This is page (1).)

%%Page: (Back Page (2)) 2
% Page 2 text
/Times-Roman findfont
1.0 setgray
60 scalefont
setfont
newpath
100 200 moveto
(This is page (2).)

showpage

%%EOF
%