>This Goes In The "LostFocus" Method of a ComboBox:
>

>If !Empty(selFactura)
>        xFactura = FacturaS.Factura
>	xValor   = FacturaS.Valor
>	xBalance = FacturaS.Balance
>
>        Select FacturaSC
>	   Append Blank
>	      Replace FacturaSC.Factura With xFactura
>	      Replace FacturaSC.Valor   With xValor
>	      Replace FacturaSC.Balance With xBalance
>				
>	Thisform.Refresh()
>EndIf
>

>After this code (nothing difficult I think), the focus must go to the next control in the tab order, which is a Grid, but the Grid never gets the focus. I think that the focus never leaves the ComboBox.

Check for any control that may be offscreen - with negative or overly big .top and/or .left property. Also, any control that may be behind the grid or other control. You should be able to locate it in PEM sheet, if there's such a control.

If you keep hittin the tab key (also ctrl-tab), do you eventually see a control getting the focus?