gf driver shooting blanks

Unidata folks,

I've got NAWIPS 5.6 running on hp-ux here, and I've been creating gif
images from gdplot and gdthgt regularly (both from the command line and
within .csh scripts--not from a cron), but recently, the programs will
have executed successfully, but no gif image (dev=gf|/usr...etc.) ever
actually gets created in the directory.  This has been a chronically
recurring problem, but I am not able to pin down why or even what's
going wrong.  There are no error messages; gpend runs successfully; xw,
ps, tiff device drivers all work to the correct output files; I have had
success creating many gifs in the past, but I suspect something on my hp
machine has changed.  Could this be some environmental variable
definition which is incorrect, or could it be a permissions problem?
(but that would send an error message while running the program,
wouldn't it?)  If it helps at all, X is running on the machine, and we
are using the CDE interface.  I could use imagemagick I suppose, to
convert from postscript files, but why bother when the gf driver has
worked in the past?

I'm out of patience with this---I believe that the gf driver had
problems in previous gempak versions, but I know it's been fixed.  I
wish I knew why it was working once, but not tonight.  Any help you kind
folks can offer is greatly appreciated.  Thanks.

Dan St. Jean
NWS Burlington VT

begin:vcard 
n:St. Jean;Dan
tel;fax:802.660.0705
tel;work:802.658.0207
x-mozilla-html:FALSE
org:DOC/NOAA/National Weather Service;WFO Burlington VT
version:2.1
email;internet:address@hidden
title:Senior Meteorologist
adr;quoted-printable:;;Burlington International Airport=0D=0A1200 Airport 
Road=0D=0A;South Burlington;VT;05403;
fn:Dan St. Jean
end:vcard