Google has changed its algorithm over 400 times within the last year. That means over once a day!

We are now in what as known as the "everflux." Rankings on the results pages and your Google toolbar page rank (less important than you think) are/is highly volatile.

The best thing for you to do is to cover the entire technical landscape of that which their algorithm analyzes. So in order to increase and keep a consistent page rank (when either their algorithm shifts or stays stagnant) you need to employ excellent on-site tactics (strive for W3C compliancy), use semantic markup, provide the internet community with unique, information rich content, and build good quality links to your site.

Google works in mysterious ways ! Please don’t worry about page rank. Concenrtate on getting visitors to your site. Make sure lots of people link to your site. It is good content , not page rank that matters. Some good websites have lots of visitors bu a crap page rank.