You do not have to have only one Lamp Module on any X10 Address.
You should be able to have more than one on E8. If you had a mixture of the newer Soft Start and older before Soft Start. Then you would have to had them all defined as Before Soft Start in AHP.
Off but not On can be an older before Soft Start Lamp Module defined in AHP from the Lamp list and not the Old Before Soft Start list.
Sometimes older X10 modules House and Unit Code Dials become intermittent and they are on a different address than the dials indicated.
Rotating both the House and Unit Dials a few times. Frequently clears up the incorrect address.