Is it possible that the table apInvItems has no records?

>Greetings community
>I have a combo box that disables as soon as the control source is set. PONum is defined as character 6. No problems if I comment out the controlSource line of code. I have also attempted to run without the .boundTo and .boundColumn with the same result. setting enabled = .T. as I do in the code before and after does no good. The data is numeric, but the field defn is character.
>Clueless in Bath. Thanks in advance
>Vince
>

>SELECT p.poNum, p.vendCode;
>       FROM poMast as p;
>       WHERE p.vendCode = vendMast.code;
>       ORDER BY p.poNum;
>       INTO CURSOR tmpCurPOs
>...
>thisform.clsdatadesc.cboponum.Enabled = .T.
>
> WITH thisform.clsdatadesc.cboPoNum
>     .controlSource = "apInvItems.poNum"
>     .RowSourceType = 2  && alias
>     .rowsource = "tmpCurPOs.poNum, vendCode"
>     *.rowsource = "poMast.poNum, vendCode"
>     .columncount = 2
>     .columnWidths = "50,50"
>     .boundcolumn = 1  && listValue
>     .boundTo = .T.
>     .requery
>     .enabled = .T.
>ENDWITH
>