How it happens?
Few months Back Google (Matt cutts) clearly explained that Google is no longer updating page rank algorithm for the websites.
How to be safe out of Google page rank smashes?
Google use number of methods to rank our websites in that the most common thing that everyone should follow is listed
1. Include clear details about the what your website is about on your home page
2. Don’t submit your links on the spammer website
3. Spammer website may bring more traffic but you are not going to get anything out of it.
How to increase my website ranking after this Google page rank updates?
Here is the list of steps to be followed
1. Search for the link that is penalized by Google and remove it.
2. Update lot of fresh content on your website regularly
3. Give some internal links in between your contents
4. Also submit few supporting links with the content on your webpage(Wiki, mashable etc.,)
I know few people got good ranking and some of them got drop in rankings, Hope by following the complete Google updates you can achieve your desired results.
Here few links that helps in understanding more about these Google page rank updates