Mediatype and Duplex command in a PostScript print file

Hi All,

I am sending a Poscript print file to an HP4650 printer which has a built in duplexer. I need the file to print duplex, but, turning duplex "on"  at the printer is not an option as we also print simplex documents on it. My file also has a "mediatype" call to pull perf paper. I've checked the .PPD file for the printer and found the command structure for duplex and for the mediatype commands. If I use the duplex command by itself, the file duplexes. If I use the mediatype by itself, the the file pulls the perf paper. If I use the two commands together in the file, it pulls the perf, but prints simplex, not duplex.

Here are the commands I'm using - they are located in the %%BeginSetup section which is immediately following the %%EndProlog and is prior to the actual print data in the file. Can anyone tell me why the two commands won't work together or how to coorect my code? Thanks!

featurebegin{

%%BeginFeature: *Duplex DuplexNoTumble

  <</Duplex true /Tumble false>> setpagedevice

%%EndFeature

}featurecleanup

featurebegin{

%%BeginFeature: *MediaType Perf

  << /MediaType (Perf) >> setpagedevice

%%EndFeature

}featurecleanup