Got kind of a bad feeling about this but I'll dive in...
Since your projector has all those inputs it surely can be driven with an analog signal and your NV card can do that. But first....
Can you confirm projector is working from another source (cable box maybe?), preferably via VGA cable?
Your laptop has only VGA output, right?
Have you looked at the Nvidia "read me" stuff on their site? Especially the TV-out stuff?
Since you've changed everything can you send a new bug report with projector attached to VGA?
(And the stupid questions, of course..) Is the projector set up properly? Is input mode selectable? Kids been goofing with the remote maybe?