Is there a shared user database between all these sites? I personally do not think so, but why is there not one I better a question.
All the themes are different (which I do not mind) but the links are all different and they are not organized at all. I think in all the subdomains need some cleaning up when it comes to links, themes, and the usertables overall. Each one has its own sourceforge project and needs to be linked to that site.
I have to say I love PostNuke and the dev team, I am just shooting a question to the admins of the site.