Oracle + Delphi: "At beginning of table" errors with dbGrid

Hi there.

I've been having problems with Oracle 7.x and Delphi 1/2.
I've got a dbGrid linked to a datasource that's linked to a query. The
query is a simple select statement from one table, returning a live
result set.  When I add a record into the dbGrid (fill out a row) and
then press tab, to go to the next record, I get a "At beginning of
table" error and the record I just inserted disappears, although it is
clearly added to the underlying table. When I then close and reopen the
query, the record pops up just fine in the Grid. I then try to add
another record with the same results, i.e. "At beginning of table" and
the record disappears.

Any help at all on this one would be greatly appreciated.