So I have to say that my most recent experience with Dell Support has been a good one. I have a D630 that would make any projector I would plug into make a clicking sound. I used the Dell chat support service and after explaining that it was happening on multiple projectors, she put in for a replacement of the motherboard. One week later the support rep showed up, put in the new mobo and no more clicking.
I am writing this post to help those that like me could not find any information on the issue. The support forums that Dell has were not conclusive. So if you have a latitude with the NVidia chipset and you hook up to a projector that starts clicking oddly, call support and have them replace your motherboard. You won't be sorry.