The screw was in the plastic cover when i took it off to have a look as it sounded like it was sparking. I dont know where it has come from and i can see a spark when you pull the light. The wiring is black and red.
The screw has come out of one of the terminals clamping the wire ,this is why it may be sparking, look around were the wires go in , make sure the power is off to the lights.
Dave the electrician, February 2009
Sounds like a pinch screw from one of the terminals securing the two wires you mention
Don't fiddle in there before ensuring the supply is isolated then pull on the wires to check secure fix
