Partially Solved MC refuses to print one file

I have a number of files that I've been working with.
One which a co-worker created in Solidworks. That file loads, and looks ok, but when I tell MC to print it, MC flickers and tells me "preparing to print" for maybe 1/10 second, then back to "Next Print".
Other files in the queue are working.

Ideas?

 

Ok, I ran the file through Netfabb, and it cleaned up something that was causing problems.
I have no idea what. That was more of a "it couldn't hurt (much)" step than a "This will fix it".

 

there's a crap ton of bad files out there that won't slice. You can usually see the problems in the slice preview.. but not always.