ghostscript error

[John Maheu <jmaheu@raemac.econ.ualberta.ca>]

I just noticed that the last two print jobs ended with a last page
printing something like

Operand Stack: 247 0 
Execution Stack:  ??



both were ps files,


/var/log/lp-err shows

------> /var/log/lp-errs <------
Aladdin Ghostscript: Unrecoverable error, exit code 1
/etc/magicfilter/ljet4-filter: /usr/bin/gs  -q -dSAFER -dNOPAUSE -r600
-sDEVICE=
ljet4 -sOutputFile=- -  failed
------> /var/log/lp-errs <------
Aladdin Ghostscript: Unrecoverable error, exit code 1
/etc/magicfilter/ljet4-filter: /usr/bin/gs  -q -dSAFER -dNOPAUSE -r600
-sDEVICE=
ljet4 -sOutputFile=- -  failed


Anyone know what this means - I 've never had this problem before?
Running slink with gs-aladdin 5.50-3, HP LaserJet 6P.  

Thanks
John
--------------------------------------------------------
John Maheu                phone  (780) 492-2049
University of Alberta     fax    (780) 492-3300
Dept. of Economics        email  john.maheu@ualberta.ca 
Edmonton, Alberta
Canada, T6G 2H4
--------------------------------------------------------