Here is a problem I never experienced before:
I tried to import an IGES file into a new scene in Keyshot 3 and I get the message that there is no 3D geometry in the file. Nothing I could do.
However, when I tried to import the exact same file into Keyshot from my wife's login (same computer) it works perfectly... Same happens to WIRE files.
In version 4, from my login, Keyshot opens the file, but without any geometry. From my wife's login, no problem again.
Yeah there's something fishy 'bout that "no geometry found" msg ... I sometime get that msg when importing an Inventor assembly and without changing anything, it does import just fine the second try.
We will investigate.
Can you try to run as admin to see whether you get different results?