Can't get no DataRowView from my bound combobox no more

Hey All,

I've got a winforms project that I converted from 1.1 to 2.0
w/the vs
2005 wizard.  One of my forms has 2 combo boxes, both bound
to different
DataTables in a strongly typed dataset.  When the first
combo (cmbStudy)
changes values, I need to change the filter on the DataTable
to which
the second combo (cmbStatuses) is bound.

The below code worked fine in 1.1, but I'm now getting an
Invalid Cast
exception when I try to convert the contents of
cmbStudy.SelectedItem
into a DataRowView.

   Private Sub cmbStudy_SelectedIndexChanged(ByVal sender _
      As System.Object _
   , ByVal e As System.EventArgs) _
   Handles cmbStudy.SelectedIndexChanged

      Dim strFilter As String = "Study = 1"
      If Not cmbStudy.SelectedItem Is Nothing Then
         Dim drv As DataRowView
         Dim s As MENU.StudiesRow
         drv = CType(Me.cmbStudy.SelectedItem, DataRowView)
         s = CType(drv.Row, MENU.StudiesRow)
         strFilter = "Study = " &
s.Study.ToString
      End If
      MENUTrackerApp.MENU1.Statuses.DefaultView.RowFilter =
strFilter
      BindStatusCombo()
   End Sub

Interestingly, the thing occupying that SelectedItem
property at runtime
is something called a
System.Data.DataViewManagerListItemTypeDescriptor,
which doesn't seem to exist in the vs 2005 documentation, or
in the
object browser.  If I type in 'dim x as
System.Data.DataViewManagerListItemTypeDescriptor' I
immediately get a
'Type System.Data.DataViewManagerListItemTypeDescriptor is
not defined'
error.

Can anybody hip me to the new method for getting a reference
to the
DataRow representing the currently selected value in a bound
combobox?

Thanks!

-Roy