Are you using the the Yellow pin to skew the image?
That's UVW mapping which is not the same as your regular UV mapping which is purely 2D.
If you skew an image in SketchUp you can introduce additional UV points so a plane with 4 verts could have 5 points when you view the UVs.
Hopefully this shows what I mean. I think if this type of mapping is where the issue may lie.
Either its the new engine thats flaky or the destination app does not support UVW mapping.
I could be wrong.....it has happened before....many many times.