currently have the yamaha lpx-510 and may be able to get a good deal on a mitsubishi hc 4900 is this a worth while idea?

Last year I had a Yamaha LPX-510 installed in my dedicated audio room. I was surprised to learn that the projector didn't have a built in VGA connector for a laptop connection. My installer had run a VGA cable from a wall outlet to the projector and then connected a VGA to component adapter (via a female VGA to female VGA adapter). The component cables are now in the Input B spot. I have tried connecting 3 laptops and none of them will project an image. Two of the laptops were Apple Powerbook G4, one a 12" (mini DVI connector) and the other a 17" laptop with full size DVI. I have connected the two Mac laptops to the the VGA connector using the VGA to DVI dongle with the 17" and the VGA to mini DVI dongle for the 12". Yet, when I connect the laptops, I don't get an image on the projector using input B (component). The laptops recognize the projector, but the projector says not supported. I have fiddled with both laptops, pressing F7, changing screen resolutions, refresh rate, mirroring vs. no mirroring. Thinking it was a Mac problem, I tried a Sony Vaio PC and still could not get the laptop to project. Usually, I have no problem connecting any of these laptops to LCD or DLP "data" projectors at work to give presentations. Any suggestions. I am desperate.

Hey guys. I'm new around here, but I've already found a great deal of info here. I'm in the early planning stages of a dedicated HT room to be built sometime next year. The room will be roughly 16'x21' with the "effective" area being 16'x~17.5' because of the arrangement of the gear closets in the rear. I'm going to use a FP in the room and was guessing on a budget of around $3,500 for the FP and the screen. Is this doable? My seating positions will be about 10' and 14.5' away. I was looking at a 82"-92" screen. I'm just getting my feet wet with respect to the various brands that are out there, so all help in that area is appreciated. I did get a chance to demo a Yamaha LPX-510 on a Vutec silverstar screen. The projector looked good, but I did notice the same thing the reviewer at this site noticed about the silverstar. Off-axis viewing was noticably darker than the on-axis viewing. It was severe enough that I probably wouldn't go w/ that screen. Anyway after all that, if you could give me any/all thoughts and suggestions on projector/screen combos in the $3k-$4k price range, I'd appreciate it. John