>Maybe there's some cruft in a proc file - a bad character such as CHR( 0 ). Or maybe some orphan code, outside of a PROCEDURE/FUNCTION...RETURN or PROCEDURE/FUNCTION...ENDPROC/ENDFUNC.
>
>I think FPW had a 64K limit on the size of a compiled proc file (which in practice is quite a lot) but I sometimes saw code that exceeded that, but you would usually get a compile warning.

Definitely not a 64K size problem. But I have a nagging feeling that orphan/spurious code was to blame. I initially did indeed have some orphan code between the main proc's RETURN and the UDFs when the problem arose -- but I subsequently either commented it out or cut it out (I'm quite sure...famous last words...), and I still saw problems. I did not type everything in from scratch as I built up another prg file in an attempt to isolate the culprit -- I copied and pasted section-by-section from the original -- so a spurious character could conceivably have been carried over. I never like moving on without a definitive understanding of what was happening, but the task list is long and enough is enough! Thanks again for your feedback.

-m.