Ive just moved into a new house and have a problem with the lounge lights, it has a double switch, one for the ceiling light & one for the wall lights. The problem is that if I have the wall lights on and then switch the ceiling light on, the wall lights go off, if I them turn the ceiling light back off the wall lights will come on again! Could this just be incorrect wiring on the switch or may it be a little more complex than that?