Grounding Issue/Electrical

I recently grounded a wall outlet that a Monster line conditioner said was ungrounded-- by extending the ground screw so it touched the wall of the outlet box. Now one line conditioner (a voltage stabilizer) shows that it is grounded, but the second line conditioner, which is plugged into the voltage stabilizer, does not show that the ground is okay or that the wiring is proper (lights are off or barely on). Anyone have any ideas or tips? Very much appreciated.