Rounds do not complete in Creo

I am finding that some edges on a simple rectilinear model will accept a round of say .125 radius on a 4 inch side, show the geometry but not remove the model material which would be gone if the round completed.

I've tried starting with different simple models and it fails on some and not others. There may be a common origin of the trick edges like they are edges created by an extrude.  I haven't gotten to sorting this out.

I've been running Creo and Pro/e for a very long time and have never encountered this before.  

What would you look at assuming this isn't a bug?

If this query is not posted in the correct area here, let me know.