I loaded the ILDA test pattern as a scene in Moncha but Moncha does not properly display it. Only a portion of the frame is displayed most of the time. Every now and then, the complete frame will be displayed. Other frames appear to work fine. Could you try displaying the ILDA test pattern with the Moncha to see if you can reproduce it? I cannot tell if this is a software or hardware problem. But, I have not had any trouble displaying this pattern on my galvos with my other lasershow software/DAC combo.
Also, there appears to be a little bit of flicker when displaying some of the frames.
Is it possible that the timing of when to start drawing the next frame is incorrect?