Yes i had exactely the same problem with mine.
Carry out this on both left and right side until problem is fixed:
If you gain access to the rear lights area by opening up the storage hatch and removing carpet and foam padding. Put your hand through the gap and remove the black plastic connector block that connects the wires to the light unit.
The problem is caused by loose connections between the block and the pins it grabs on the rear light casing. use a screw driver to push each of the 6 or 8 "u" shaped clamps a bit closer together. Hope fully this will cure the problem.
A more long term fix would be to remove the connector block and solder the the coloured wires directly onto the light casing.
hope this helps.
tim
January 2008