Help with simple conditional?

[Fairlight]

I cannot believe this is not working.  I have no idea why so far.  I
double-checked the manual to make sure I remembered it correctly. 

I'm doing a key field lookup.  It succeeds.  If I take the conditional out,
it will list every record.  The line I have problems with is this:

If: sintest(1) co SearchTerm
Then: goto skipit

I originally had:

If: not sintest(1) co SearchTerm
Then: getnext sintest;goto loop

Either -should- work, as far as I remember.  SearchTerm is definitely
defined and populated, as I've written the value to a logfile.  I have
tried different values for SearchTerm that I know are substrings of field 1
in various records in the file being looked at.

If I use either method, I get no records matched.  If I comment out the
relevant tests/logic, I get all records, so I know the lookup is good.

Is there some trick to using the 'co' contains operator that I've
forgotten?  I haven't used it in years in processing.  I usually only use
it in IUA short selection.

fP 5.0.14, Windows Native.

Thanks in advance...

mark->
-- 
Audio panton, cogito singularis.