Another Penalization Question

[hotnewfilm]

First off, let me say that I've been reading this forum for quite a while, and I find the debates and discussions consistently engaging and extremely helpful. Now, for my first post on the forum:

I'm a relative newbie on how Google, SERP, and PageRank works. I run a very popular site that's had a PR6 for quite some time. All the pages in the first directory down are also PR6, and as such I always figured that all my pages in the root directory are nearing PR7. Regardless, last least the page rank on my home page disappeared completely. I'm still linked on Google (no problems there), and all my other pages besides the home page still have their PageRank. So, is this a temporary glitch (I noticed that a colleague with a similar entertainment site also lost his homepage PageRank on the same day as I did) or is it possible for Google to penalize a site's home page but no other pages? Should I contact google ([e-mail]) about this?

I'm probably being paranoid, but I din't want to necessarily call attention to the page if its really only a glitch...thanks...