APPIAN AND MOTION DC30 PLUS

[AUDIOPOLIS]

We have big problem with the following configuration .
We are using the G4/500 Dual proc. computer with 7 slot exp chassis ATTO SCSI card and the Miro Motion DC 30 PLUS video card and the Appian Jeronimo 2000.
The graphics is much slower than with the original Mac Graphics.
But the worst thing is that when we start using video in session - small quick time movie on screen and the video PAL output from the DC 30 The graphics is even slower and by dragging the window or similar operation we get the system error warning that the PCI bus is overloaded.
The question what is really going on because the described configuration is one of recommended by digidesign !