We had a double 2G G5 with the ATI 9800.

We ran from display propertys both outputs on 3072 x 768 with triple heads.. I hardly got that working from the Apple. Starting up Catalyst then en entering full screen.. No output what so ever and NO HUD's...

I was running m92 you send me for this show...

Ruediger tested this simultane in Germany on a G5 as well with another build and got the same result.