Strange Error: Run-Time 3707 Database Engine does not recognize name

I used this same exact code on a few other comboboxes with no problem... I can't understand why it's not working this time... I even changed the fieldname thinking it might be a keyword... MS help says it's probably misspelled but I copied it out of the table design...

Any idea what might be happening?

Code:

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Private Sub Combo43_AfterUpdate()

    Dim st As DAO.Recordset


    If Not IsNull(Me.Combo43) Then
        'Save before move.
        If Me.Dirty Then
            Me.Dirty = False
        End If
        'Search in the clone set.
        Set st = Me.RecordsetClone
        st.FindFirst "[MState] = " & Me.Combo43
        If st.NoMatch Then
            MsgBox "Not found: filtered?"
        Else
            'Display the found record in the form.
            Me.Bookmark = st.Bookmark
        End If
        Set st = Nothing
    End If
    Me.Combo43 = ""


End Sub

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Resolved! It is defined as text!