Does it work sometimes? mines intermittent, so I ignore it - luckily it seems to work when I need it though!!
Its the switch on mine i've concluded. Its in the catch so I'm not up for a poke around there!!
there is only one fuse covering both interior lamps, the front one works ok.
i believe that both int. lamps should come on at the time when the front doors open.i think the same thing happens when the rear door operate.