Problem with 3ds max unwrapping UVWs

[jasonsmithgoat 13]

I'm having a bizarre problem that I can't seem to fix. I'm drawing the model out in Sketchup and then importing it into 3ds max for unwrapping. For some reason 3ds max is adding seam lines where I didn't put ones and then projecting them incorrectly. For example: 

As you can see in the picture above 3ds max injected a line in the middle where I did not mark. The exact same thing on the other side doesn't have that line in the middle. As a result of this the cut out part is projecting as a slash which I can't do anything with.

How do I fix this? I am using box projection FYI. Other projection methods don't look right at all so box is what I'm using.

[Koesj 659]

What does the geometry look like before you apply the UVW Unwrap modifier? Just straight op editable poly > polygon selection > edit triangulation. Or back your file up and go and mess with vertext selection > connect on a fresh version to figure out how your file is being read by Max.

I myself started out with some Sketchup models and zero Max skills, and ended up completely doing my stuff in Max since the import process creates all kinds of problems (duplicate vertices and polys, ngons, mirrored and inverted faces, etc.)

[Darf 1,439]

You mean the white lines? They are just the edges of your ngons. Import out of sketchup does nothing strange if you do it the right way.  The slash is due to autoprojection of 3ds max. Sometimes it divides polygons up if it can't decide what angle is the best. Click on the polygons and press the flat projection around an axis.

[jasonsmithgoat 13]

I got a workaround in place that fixes the problem, unfortunate it adds a bunch of triangles but I think I'll be OK with this. I included an extra set of vertices to "weld" the polygons in place.

My best guess is that something is off by millimeters, something that I can't see or really do much about in Sketchup. If I copy and paste the left side onto the right side and try to weld it in, some of the lines have extra endpoints in the segments. It sounds like Sketchup is adding breaks in to try to hold it up but my attempts to fix it hasn't been successful.