Just bought this thing, hooked it up to my laptop (correctly!) and the projector is supposed to then automatically find the source (i.e the computer) and, well, start projecting. But absolutely nothing happens and all I get projected is the Acer logo and, very annoyingly, the "no signal" message. I'm not much of a computer head so I'm baffled - is there something very simple I should be doing? Despite the thing saying how easy it is to use - "just plug it in and off you go!" Yeah, right! Any help very gratefully received.