I just thought I would share this: my 3300MP started a cycle on startup, where it would power up, reset, power up 5 times, then display a message 'Lamp Failure'. I was researching lamps but could not see any from respectable re-sellers
I then went looking on forums for suggestions, and came across someone who mentioned that you should clear dust and try again, and that the lamp may not be faulty. I did as suggested, and noticed when doing this that the cover for the lamp section was slightly loose, and that the screws had gone through the plastic (i'd never been near that so I don't know how this happened). I thought nothing of it until I read another post saying that the projector 'knows' that the cover is in place, as there is a metal connection that needs pressed in.
In desperation I taped the cover back firmly in place, and hey presto, the lamp has started working again. I removed the tape and the same Lamp Failure message occurred. I've now fixed the cover back in place with new washers and everything seems to be working perfect. That saved a lot of hassle getting a new bulb, which would not have solved the issue.