I compiled the trunk (revision 11362) for pcl (with ufst).
in main: nmake -f pcl6_msvc.mak DEBUG=1 TDEBUG=1 MSVC_VERSION=9 PL_SCALER=ufst

when run at default resolution (72dpi).

devenv debugobj/pcl6.exe
with project-properties:
  -sDEVICE=jpeg -sOutputFile=/dev/null -dNOPAUSE J341.pcl J341.pcl J341.pcl
and breakpoint set at plmain.c:line343: if (!filename)
   where it gets the name of the next job on the commandline.

set a watch at: (gs_malloc_memory_s *)(pjl_mem->non_gc_memory) and look for used/max_used fields.

you will notice that used/max_used will not grow after the 1the job has been processed.

Do the same with resolution 150dpi.
project-properties:
  -r150 -sDEVICE=jpeg -sOutputFile=/dev/null -dNOPAUSE J341.pcl J341.pcl J341.pcl

you will see that used/max_used will grow at each break (start of next job) with about 5-6MB per job.

There seems to be a memory-leak related to non-standard resolution (! 72dpi).

The testfile J341.pcl is from a very dumb application (downloading 2 fonts over and over again (using different softfontids), so the job as such uses a lot of memory. What was surprising is that memory consumption keeps growing with each time the job is processed (also to be seen in the taskmgr of windows).