Man, that would be great to know.  I have no particular favor to B7.  If B6 will allow checking up on a long render, that will be the route I go next time.  That brings another question:

 If a scene in built and saved in B7, can it be opened and rendered in B6?

 I know the opposite is true.  I'd check it out but that will be at least a week from now.  How in the world did you ever discover this easter eggy thingy?