It looks like your error was a configuration issue. Here are the steps we took to resolve this. Please note that we used PATHWORKS version 1.2, but we think version 1.1 should act the same.
1) Printed the file that you gave us using the LaserWriter Utility. This verified that the file was good, and that the printer could handle the PostScript level in the file. It worked fine.
2) Ran the following command procedure which deletes the queue from VMS and PATHWORKS, and then re-initializes the queues with the proper PostScript parameters.
$Set ver
$ set noon
$ stop/next laser_que
$ del/que laser_que
$admin/msa
stop printer/all
remove printer "LaserWriter 600 Printer"
ADD PRINTER "LaserWriter 600 Printer"/QUEUE=Laser_que -
/DESTINATION="Selway@ZONE NAME E"
/SHEET_SIZE=(A4,B5,LETTER)-
/default=(flag, Trailer, Form=ps_plain)
start printer "LaserWriter 600 Printer"
exit
$set nove
Note: Our old init file did not have the /sheet qualifier and the /default=(form=ps_plain) qualifier. Also, Selway = LW 16/600 name, ONE NAME E=zone name.
3) We printed your postscript file using the same command you did, $print/que=laser_que a.ps/param=(data_type=postscript), and it worked fine.
4) We then verified that the queue would still print text by using the normal print command for login.com $ print/que=laser_que login.com.
Our recommendation is that you upgrade to PATHWORKS 1.2 and then re-initialize the queues using the preceding commands.