frame size / rendering / multiple screens / triplehead2go

I have managed to confuse myself totally about output frame sizes...

Apologies for the long post...

I have been experimenting with a matrox triplehead2go - interesting piece of kit, but I seem to have a disconnect between frame size being rendered in VMS, and what will display.

I have a slide show of images, each key-framed with track-motion to move across the screen over a 15 second timeframe. For a local school show, we want to have the images move across three screens - one on either side of the stage, and one above it. The images will start on the LHS screen, move across to the middle one, and then move onto the RHS screen.

I have connected the triplehead to my pc, and have 4 monitors connected - the primary monitor is directly connected to the first output on the video card, and the remaining three are connected to the matrox connected to the second output on the card. The matrox treats the three screens as a single 1920 x 480 screen, each screen set to be (640 x 480).

By my reckoning, that if I set my project properties in VMS as (1920 * 480), my rendered output should fill the three screens - which it does not.... If I open the rendered avi file in windows media player (or real player) the images only play in the center screen, plus approx half of either of the side screens - so it looks like it is rendering at about 1200 x 480, but yet when I look at the avi file with mediainfo, it does show 1920 x 480...

So my questions are:

- Am I correct in assuming that if I have set the output horizontal and vertical options in my project options as 1920 / 480, that I should get an output file that will fill a screen that is in effect set for the same resolution?

- As an aside, has anybody got any experience in showing a single video split across (and filling) multiple displays as controlled by a triplehead2go?

Note - this is not the same issue I posted about in the live-events forum - in case cross-posting is an issue...

Many thanks for any suggestions...

Stewart Bourke