Ok,
I see the reason in the release notes:

"I added the capability to use a TStringField to handle an underlying
column of type large integer (BIGINT). This is to work around a
problem with the TDBLookupCombo control using variants to handle the
values, which fails with largeint types."

Rene

--- In IBObjects@yahoogroups.com, Hans <hhoogstraat@s...> wrote:
>
> cant do that, unless CBuilder at times. Both must be AsString
>