Why Would PageRank Drop From 4 to NA?

[PatrickGriffith]

Yesterday my homepage had a PageRank of 4 according to the Google toolbar (which I know isn't accurate, but bare with me) and the majority of my other pages were PR2.  Today every page on my site is PR N/A, or PR -1.  I also used a couple of free page rank checkers to make sure it wasn't just my browser.

The only link I have ever purchased is on botw.org.  I submitted my site to 6 free directories about two weeks ago, but only to the highly recommended ones, and with different anchor text at each.

I have no messages in my Google Webmaster Tools account, nor do I have any significant crawl errors.

My SERPs and resulting traffic have not (yet) been affected.

Any ideas what's going on? I did start a Google AdWords campaign about 10 days ago that ran for 3 days and then got suspended due to the nature of my website. Could that be it?

[Discountvc]

There has not been a PR update in the past few days (as far as I know). Therefore it is doubtful that your browser PR return is steered by G, but something else is overtaking your stats.

Your site is hosted on a shared domain. If something happens to any of those sites, your site would/could see an immediate effect.

I would move away from sharing the same URL and go for hosting on a dedicated server.

Good luck!