From what I've been able to ascertain from reading your posts it could be the way you have things hooked-up requires something like this? http://www.cablestogo.com/product.as...engine=adwords!654&keyword=%28component+to+vga+adapter%29
Again, it would be helpful to know what inputs the projector has. For example, does it have a component input? If so, you can try a component cable (or 3 separate composite video cables) and see if you still have the problem. You can move one of the devices closer to the projector if you have shorter cables.
I went to JVC's site and could not find that model no. for the manual. Unless there was some problem with cabling or with the proj. settings, I find it hard to believe that all 4 devices would not pass a progressive signal. Usually when you output to a device that is not set-up for a progressive signal you get a wavey type image that moves around (best way I could describe it anyway) that looks squashed.