Quote - Any clues as to what the bug is ?

No, but...

We have three cubes, mine, Paloth's (only pictures), and markschum's.

Each cube inherits the wrong colour from a different face, the top for mine, the front for Paloth's, and the bottom for markschum's, but the face that inherits the wrong colour is the same in all three cubes. Can this just be coincidence? All three cubes were created in different modelling applications.

There is some room for verbal confusion here, because I call the "right" face the face that would be nearest to the cubes right hand if the cube were to be given hands, where as markschum calls the "right" face the one that is seen to be on your right hand side when looked at from the front. I'm not saying one is correct and the other wrong, just pointing out that we need to be careful that we understand what each of us mean by "right".
P.S.
Here in the U.K. a car driving on the right side of the road is driving on the wrong side of the road!

:blink: