Barco G808: computer sync probs and convergence probs

Own a Barco Graphics 808, any ideas on hooking up a pc to it? Whenever I try my laptop via a vga to 5 bnc cable to port 4/5, unable to obtain a good image, i was told that i needed some kind of interface box between laptop and projector to enable the pj to sync in. Is this correct?? Also, anyone with convergence problems on top left hand side of image converging red and blue on green? Apparently, again so i've been told, a common problem with Barco's. it appears that the last two vertical lines on grid pattern are at different distances so that you are only able to converge one line accurately (applies to both red and blue). Anyone know of this prob?? Help appreciated as driving me slightly mad!!

 

The graphics 808 requires negative syncs input 5 will be for RGB and then the syncs either combined (c) or seperate (H&V). Input 4 is for sync on green. A PC interface will perform two jobs provide the projector with negative sync and bring it up to the correct voltage. Most modern video cards can be set with a bit of software called power strip and most now can supply sufficient voltage to drive the projector provided the cable run is not too long.

The convergence issue is an anoying one and I hope one day to spend some time getting to the bottom of it. (sorry Uncle Eric)
When your convergence is set to midpossition are the R&B vertical and hozontal lines absolutely parrell to the green or does the vertical skew?