I have a page on my site that had PR3 and was up in SERPs, not it is "unranked" and disappeared from the top 100 results. I am wondering how can this happen? The content is the same, I have the same links, etc. Everything is as it was before. Any ideas?
If this was a new site I would give it two weeks and see if you reappear in the SERPS. It may just be the Google dance. If it is an older site then the latest algorithm may not like your site and you have some work to do to get your ranking back.
It is a sub-page of my site, not the homepage, the homepage is PR4, unchanged. None of my domains changed PR recently, only a few subpages fluctuated.
I had the same thing happen to one of my PR4 inner pages. A couple of weeks later is bounced - with a PR2
Without having seen it myself, it's hard to say. Has the page moved further away from your home page, like from the second page of a blog to the 3rd? Is the URL the same? Sounds like a google slap, but given your home page staying the same that might not be it either.