Nissan Micra (V reg) Reverse Light Stuck on?

I have just bought a V Reg Nissan Micra. Before my MoT I checked all the lights only to notice the reverse light was not working. When I went to replace the bulb I found there was no bulb in it. I put in a new bulb but as soon as ignition is turned on, the reverse light comes on, no matter what gear is selected, or neutral.

Any ideas?