Matrox BIOS update and download and installation of latest Matrox drivers fixed problem. Direct-X now fine.
There's also an irritation that the OEM logo on bootup is scrambled (can't disable it on this system), this is due to the mode used not being supported by the P650 BIOS on bootup. Matrox have a little download on their site that fixes this.
Now time to stick in the AV (I use McAfee's Internet Security package and have had no probs with it) and get online.
Still tinkering with the FREESCO router on an old P1 at odd moments. And my area has just got ADSL, so I suppose that that will be the next project.