Hi Keith, from the look of it, that is likely to be a display glitch - probably the display mesh that was generated didn't get enough triangles in that area to make it appear smooth.

See http://moi3d.com/forum/index.php?webtag=MOI&msg=1308.2 for some tips on how you can adjust some settings that may help (but can also cause an overall increase in mesh density which can slow down the display as well).

If you can post your .3dm model file (or send it to me at moi@moi3d.com), I can double check it to make sure that this is indeed the issue or if it is actually something wrong with the surfaces.

I will be trying to improve this in the future, but it is a tricky thing to improve it without slowing the display mesh generation down too much.

But if it looks fine when you actually export, then it is just best to ignore it.

- Michael