RNX9001 - Internal failure in compiler

Any suggestions on how to debug the error RNX9001, Internal failure in compiler?

I'm only getting it intermittently, and haven't isolated the conditions of when
it fails vs when is works.  The general scenario is:

  - Win32 software (UPS Worldship) performing INSERT to table via ODBC

  - Host machine is at V4R5, ODBC softare from Hit Software[1]

  - Trigger on AS/400 PF invoked, *CALLER activation group, LR off
    (This program does not access any other files directly, but does use
     AlwRepChg(*Yes) to potentially modify the record buffer.)

 - Depending on the data, the trigger also calls another RPG IV program.
   This program is also compiled *CALLER and returns with LR off.  It is
   called via a named constant with the library explicitly specified since
   the library is not in the list used by the ODBC job.

 - Due to library list issues, the trigger performs some OVRDBFs in its own
   *Inzsr for the sake of resolving some files opened in the called program.

 - Nested program also uses one service program, also *CALLER group.

The RNX9001 error, when it occurs, happens on the call from the trigger program
to the nested program.  The called program does not close files  I'm guessing it
may be an activation group issue and may even have to do with ODBC timeouts.  Or
it may have to do with issuing OVRDBFs in *Inzsr of the trigger.

[1] - For those following my saga, using Client Access Express's ODBC client
resulted in random errors on the INSERT, typically with numeric fields.  Since
trying the Hit Sofware ODBC client, the INSERT has been working but now I get
the other error.  Client would prefer to not need to license another ODBC
client, since Client Access is already paid for.  Suggestions on this front are
welcome too.

TIA,

Doug