Hi Chris, thanks for reporting this issue.

This must be a problem introduced with the new style of triangulation in the last beta, which breaks n-gons into triangles using a radial type style in order to avoid long skinny triangles.

That's the only thing that has changed in that area in the newer beta version.

You can disable this new style of triangulation by a setting in the moi.ini file.

To do this, close down MoI first, and then open up the moi.ini file in notepad. You can find it here:
C:\Documents and Settings\Michael\Application Data\Moi\moi.ini

Under the [Mesh Export] section, find the entry that says:
CentroidTriangulation=y
and change it to
CentroidTriangulation=n

This should cause the Nov 18th beta to handle meshing in the same way as the previous Sept beta. Can you please let me know if this solves your problem?

I will take a closer look at the newer style triangulation to look for messed up UVs.

- Michael