The order of WRKUSRJOB

We have an application that copies the results of WRKUSRJOB 
to a file and parses the results to see if the user is already running
a job via either SYS REQ or another session somewhere.

We have run into a problem where the WRKUSRJOB sometimes returns 
a blank job name (which for the interactive sessions equates to the 
workstation).  The program logic compares this value to the workstation
value retrieved from the job attributes. 

We are seeing the WRKUSRJOB return (sometimes):

Opt  Job        User      Type    ----Status----  Function
___  COMPYCRT3  USER01    INTER   ACTIVE          PGM-ARST01CL
                          INTER   GROUP           GRP-QEZGRP2

and then, sometimes:

Opt  Job        User      Type    ----Status----  Function
___  COMPYCRT3  USER01    INTER   GROUP           GRP-QEZGRP2
                          INTER   ACTIVE          PGM-ARST01CL
                          
The first version works great.  We can link the ARST01CL program to 
workstation COMPYCRT3 and compare it to the workstation value retrieved.
The second version is our problem.  The program is linked to a blank
workstation and throws us a curve.  The different order seems to be linked 
to the user value.  One user consistently gets version one, and the other 
version two.  At least so far.

What controls the order of the WRKUSRJOB panel?

TIA,

Dan Rasch - because if the human species concentrated on the really 
important things in life, there would be a shortage of fishing poles!
IBM Certified twice....... but still a couple PTFs away from Nirvana.