Try the settings over here:
https://forum.team-mediaportal.com/htpc-projects-42/migration-amd-690g-780g-40706/
thanks. based on that thread, I've been trying a lot of differnet version of ATI drivers 8.5,8.6, 8.7. mobo now on f5 bios, bios set to 512Mb video ram. still getting exactly the same problem. MP crashed part-way through startup when running display at 1080p - works just fine with 1920x1200 display.
can MP actually cope with being run at a different resolution to that which it was installed at? do other people build it the way I have? am I going to have to blat it and start again with my monitor running 1080p?
Ian