Weird program errors that I can't duplicate. Maybe activation group problems?

Two users have been reporting the same problem with one of my applications.
I have a very complicated subprocedure that calculates the taxes on an
invoice. I had one of the users try a few things, but I can't the program
to crash on-demand (though it did several times though the testing). The
error I get is "Receiver value too small to hold result." The user can log
out and in again and retry it on the same invoice and it works flawlessly.
Thus my thought it may be activation group problem.

My modules are compiled with the H-Spec of

H nomain bnddir('ARBNDDIR') option(*srcstmt:*nodebugio)

My programs are complied with the H-Spec of

H ActGrp(*caller) BndDir('ARBNDDIR':'MODULES') DftActGrp(*no)

I am by no means an expert with activation groups. Should I change this to
a named activation group? ActGrp(ARACTGRP)

--
Mike Wills
http://mikewills.me