Many site owners have been reporting a huge drop in reported Google PageRank recently. Google updates it’s PageRank report only a few times a year and it’s well known in SEO circles that PageRank is not a good indication of your sites SEO power, or success at ranking. Besides, Google is believed to misreport your PageRank just as it intentionally misreports your site’s backlinks for security reasons. Instead you need to watch your rankings and the traffic coming from Google to detect SEO improvements and growth.

Here’s Google’s official answer to PageRank related problems: 

"Don’t worry. In fact, don’t bother thinking about it. We only update the PageRank displayed in Google Toolbar a few times a year; this is our respectful hint for you to worry less about PageRank, which is just one of over 200 signals that can affect how your site is crawled, indexed and ranked.

PageRank is an easy metric to focus on, but just because it’s easy doesn’t mean it’s useful for you as a site owner."

If you worry too much about PageRank, please don’t. Even Google admits it’s a non factor.