Possible bug in DBD / Local SQL

Can anyone help with this SQL problem please. It looks
like a bug to me.

From DBD, run an UPDATE query in which the WHERE clause
includes an IN predicate. For example try running this query against

UPDATE customer SET country = 'US' WHERE CustNo IN (1221,1380)

For me the query hangs. (ie the doesn't  return control
to DBD, CPU=100%, and a multi-Mbyte _qsq.db file is produced).

An equivalent SELECT statement performs fine:

SELECT Country FROM Customer WHERE CustNo IN (1221,1380)

My Environment:
Delphi 3.02 Pro
NT WS 4 SP 4
BDE 4.51

Thanks,    Andy Garner.