return from RPGLE mod to CLLE mod errs with MCH3601

*****************************
*** CL Module
*****************************
DCL &Return    *LGL 
/* Check to see if EXCLEIACT job is running */ 
CALLPRC PRC(CHKJOB) PARM((&CheckJob)) RTNVAL(&RETURN)


*****************************
*** RPGLE Module
*****************************

P ChkJob          B                   EXPORT 
D ChkJob          PI                  like(rChkJob)
D  JobName                      10a   CONST 
 
D* Local fields 
D rChkJob         s               n                
...
      rChkJob=*on; 
      // exit at first hit.  We don't care about multiples.
      return rChkJob; 
...

I debugged using WDSC.  I "monitored expression" for rChkJob.  I break 
right on "return rChkJob".  The value of the expression is 1.  When I 
"step into" from there I get:
DBGP0003E Program received unmonitored exception MCH3601: Pointer not set 
for location referenced.
Looking at the joblog I see:
MCH3601-Pointer not set for location referenced.

From program . . . . . . . . . :   ENDLEIACTP

  From library . . . . . . . . :     ROUTINES
  From module  . . . . . . . . :     CHKJOB 
  From procedure . . . . . . . :     CHKJOB 
  From statement . . . . . . . :     1443 
 
To program . . . . . . . . . . :   ENDLEIACTP
  To library . . . . . . . . . :     ROUTINES
  To module  . . . . . . . . . :     CHKJOB 
  To procedure . . . . . . . . :     CHKJOB 
  To statement . . . . . . . . :     1443 

CPF9999-Function check. MCH3601 unmonitored by ENDLEIACTP at statement 
0000001443, instruction X'0000'.

Is this one of those CL's version of logical variables is not the same as 
RPGLE's version of logical variables?
Or is it something totally different?

Rob Berendt