[RESOLVED] Combobox binding problem

[Mark@SF]

I have a form with a bindingsource (bsMain) and a combobox (cboLinkID).

The bsMain properties are as follows.

With bsMain
    .DataMember = "Accounts"   '...this is the Accounts table in the dsMain dataset
    .DataSource = dsMain
End With
cboLinkID.DataBindings.Add(b)

The cboLinkID is bound as follows.

With cboLinkID
    .ValueMember = "RecID"  '...this is the primary key field of the Accounts table
    .DisplayMember = "Account"   '...this is the Account field of the Accounts table (i.e., account names) 
    .DataSource = dsMain.Tables("Accounts")
End With

b = New Binding("SelectedValue", bsMain, "LinkID") 
With b
    .DataSourceUpdateMode = DataSourceUpdateMode.OnPropertyChanged
End With
cboLinkID.DataBindings.Add(b)

The above code is executed with the form's Load method.

When the form opens, the selected item's cboLinkID drop-down list shows all the account names in the Accounts table. The cboLinkID.SelectedValue shows the name of the linked account. This is the expected behavior.

But when I navigate to another record, then the cboLinkID drop-down list now has no items and the cboLinkID.SelectedValue is blank.

Closing/reopening the form repeats the above behavior.

What am I doing wrong?