Well this season LBJ and Melo may actually play a lot of time at PF, and some would argue that they are actually better there (kind of like Duncan as a C), so I think that scenario isn't too bad of a deal. It's almost certain that you will have a team USA situation from time to time though, with no true Centers on the entire roster.
Also, those Ball-Don't-Lie links are the worst, they totally mess up my browser when they are posted in this forum, so I exercised some Moderator privelage and fixed the link for you.