Hi Dave,

You should be lucky with the .obj in modo, because I've got thousands of n-gones problems when using this format.
As Michael said, .lwo is much better, I can't remember when I had a flipped poly using it ... but still it may happends.

So I'm still doing an geometry>poly>align when importing .lwo object ... it works as a double flip you descibe, but it's an 'autmaic' way
so it will resolve normal problem on area you don't always notice at first sight. (Can be frustrating to discover a wrong poly after an hires rendering of 4 hours for exemple).