Adding a field for the result, even though the documentation shows it as
entirely optional, did the trick.  As a matter of fact, it's reporting an
INVALID DESCRIPTOR result, which doesn't really make sense.

Anyway, that makes it survive so the program can recover.

Is this faster than the RC or what...  And I didn't have to explain the
problem to half a dozen people who weren't capable of understanding the
problem in the first place before getting to someone that could help me
(okay, a slight exaggeration).

Thanks for help.