C'est sont les vacances ... fainéants ! :)

I am just hoping that I am not making a fool out of myself (although I have some great tendency in doing so).

Another strangeness in this model is that the two rows in east and west, those that complete from top to bottom, have surfaces created within the pentagon.

And have you tried to select a single pentagon? One that is not piped?

Very strange thing. But I guess I need to add, for the completeness of information, that this model is made using the Paneling Tools in Rhino v4, brought over using cut-n-paste. I have never had any problem going back and forth between Rhino and MoI, and I assume the issue is in PT.

I should certainly have said this in my original message§ I just hope I didn't cause a huge waste of time for investigation a problem that is made elsewhere. Very sorry! :(