Sounds a bit of a stupid idea but I read it on this forum and a few people said it actually worked.
The switch may have got jammed, so what they done was hold it about 10 - 12 inches from shutting and slam it down. It solved a lot of peoples problems, and they were saying the same thing about the alarm lights, I think it was something to do with it not alarming properly as the circuit was open and slamming the bonnet fixed all this.
Its worth a try