I had a similar problem with scaling in the export preview box. The exported image itself was fine, but pieces of my image would just disappear in the preview. (look here:
http://talkgraphics.infopop.net/1/Op...8&m=6631958462)

I never got an answer back, but I suspected then that it was related to the video driver. I am also using a Matrox card (Micron w/G-400 - home & Compaq w/G-200 - work). Both exhibited the problem I was seeing.

Good Luck,
Ric