> I can assure you that I am able to refresh single records with
> dbX, but sometimes you need to fiddle with the source dataset
> fields' ProviderFlags, that are used to build the refresh
> statement in a somewhat convoluted manner (the fault, if there
> is one, is in TDataSetProvider rather than TClientDataSet or dbX).
> HTH

Many, many thanks for the help. The ClientDataSet persistent fields
automatically come in with pfInKey set properly. I had not known that
I have to create persistent fields in the SQLDataSet as well (at
least when using Firebird--I never had any problem with the
commercial version of Local Interbase). Anyway, after creating
persistent fields for SQLDataSet, I had to manually set the pfInKey
for the key fields. Now everything works properly for both Firebird
and Interbase.

Paul