I hit error message as follows(error message trap by using Err.Desc):

Error # -2147467257 Microsoft Cursor Engine
Insufficient or incorrect key column information;
too many rows affected by update.

This error happened only when I add 2 or more similar rows of
records into the Recordset and trying to Delete one of the rows
from the Recordset.
In other words, the error happened only when I Delete the row.
The following is my code to declar the Recordset settings:

Set rsTmp = New ADODB.Recordset
With rsTmp
.CursorLocation = adUseClient
.LockType = adLockPessimistic
.CursorType = adOpenKeyset
.ActiveConnection = cnn1
.Open "SELECT * FROM DataTable"
End With
Set DataGrid1.DataSource = rsTmp