Hi Al,

>Any other objects get called that may be based on, say, the Session class?

- I don't in my code but VMP might. Will have to check.

>- Dump status information to a text file (e.g. output of DISPLAY STATUS etc) immediately before the code that's throwing the issue. You could run that in your dev environment, then at the client site. Compare the two outputs, see what differs. As a first step this can be quicker than setting up a debug environment at a client site

- this is my next step then: dump out the data session info to a text file at key points and see if it differs at all.

Thanks for the suggestions.
Albert