OK Loren I'm running out of ideas here. Based on what you said in your original message...

> All seems to work ok in my EXE, so long as it is not run from the computer used for development.

I'm wondering if your development machine points to test data (that perhaps lost an index much need for optimizing) where as maybe your exe points to production data?

To determine if your using the report's data environment, try the following:
MODI REPORT ReportNameHere
Go to View Menu, pick Data Environment
Do you see anything?