Why the actual record in a child recordset cant be changed?

I have a master-detail form with 2 grid control. Its datasources 2 adodb.command in a parent - child relationship.

Some other datasink (textbox) are bounded to the child recordset.

As I moving in the grid bounded to the child recordset, nothing to happen. The datasinks show data from

the first record.

Child recordset's actual record always the first record.

SHAPE {select * from TABLE1} AS TABLE1
APPEND ({select * from TABLE2 where TABLE2_FIELD10 = ?} AS TABLE2
RELATE 'TABLE1_FIELD1' TO PARAMETER 0) AS TABLE2

plz help