I had exactly the same problem. My boot light and interior light wasn't working, so I replaced the globes. Whilst I was doing this, I blew a fuse and my dash clock stopped working too. This is when I replaced the fuse and all 3 (boot, inside light and clock) started working again.
Try removing 1 of the door switchs, it's only one screw.
Do only 1 at a time and keep an eye on your interior light to see if it goes out.
Chances are the wire has come off and earthing it's self and keeping the light on..