'no signal' w/ sanyo projector - vista?

[Babelutte]

hi,

i bought a sanyo multimedia projector model PLC-XR201. there is no problem when i project from a dvd player, but when i connect it with my computer with the VGA cable in the Computer 1 outlet (RGB), the projector can't find the signal.

i've tried several things
-hitting the Function key and then F7, and nothing happens
- i've tried starting up the projector first and then de computer, and then i get a signal for two seconds (i see the vista sign and a static vista background which is not the same as my laptop background because i see no icons), and then the signal gets lost again
- i tried it with someone else's laptop that doesn't run on vista, and everything works fine with that one.

is it a vista thing?

[p858snake]

See if vista is putting itself into extended desktop mode?

[Babelutte]

it might have, i remember my laptop asking me something about an extended desktop, and i think i said 'yes' to it. been looking how to disable it, but can't find it. (computer illiterate here, sorry!)