Jag,
I recently installed a few of these lights in my hallway. The bulb screws into the socket, which is mounted in the center of a round metal plate. That metal plate is held by an L shaped bracket with a wingnut holding the assembly to the side of the can. Behind the metal plate with the socket in it, there are the 2 wires that go from the socket up to where the wires enter the can. If you remove the bulb, them remove the wingnut, the plate with the socket in it will drop down. You can try turning the plate, thus twisting the wires, to remove some of the excess slack from the wires. Maybe they are vibrating on top of that plate, behind the bulb...
Look
here or
here for a pic of what I am talking about... You can clearly see the wires up there in the second link.
One other thing to check if you have "remodel" light fixtures (installed in a finished ceiling by cutting a round hole, and inserting the light from below) is that the clips holding it in place are tight. When the light is installed, the clips are usually pushed from inside of the can, and they extend outward on the outside of the can until they hit the back of the ceiling. You should be able to see 3 or 4 of them inside of the can. Lightly tap each one with your finger, and see if any of them rattle...
