Hi michael

Yes it seems to be mavericks, if i leave on one screen it is more stable. I read that cranking up the canvas mega pixel value gives more detail, and in doing so it does give me a better pic, at 30 it works but at 35 it crashes every time. I have attached two pdfs a MOI version and an Isodraw version to compare. I know its unfair to compare you to such a mature product, what you've done so far is brilliant.
It seems some of the "weak" areas highlighted in pink need more resolution from the pixel grid to work but as i say it won't go above 30 without crashing. . . FYI the size of this part is approx 60cm square if that helps.

Matt