Missing something with ILE, CLLE, procs, and MCH3601

Hey All

I've got an odd problem that I can't quite pin down, and I haven't been able to
find any info in the archives or the manuals.

The situation is this...

I've got a CLLE program that does a CALLPRC like this:

   callprc prc(rpglePrc) parms(&char10 &char20) rtnvar(&char1)

My function rpglePrc looks like this:

p rpglePrc       b    

d rpglePrc       pi             n
d  piChar10                   10a
d  piChar20                   20a

   /Free

     if doStuff(piChar10 piChar20) = 'ITSOK';
          return *off;
     else;
          return *on;
     endif;

   /End-Free

p rpglePrc       b    

When I execute the CLLE program, I get an MCH3601 error.  I throw the whole
mess into the debugger and the program executes doStuff() just fine.  The
MCH3601 exception gets thrown on either of the return statements.

I know I'm missing something pretty basic here and I cannot for the life of me
figure out what it is.  The CLLE program is running in its own activation group
called INST20.

I've tried changing the &char1 parameter on rtnvar() to *LGL, but to no avail.

Any ideas?

Thanks

-Doc