Recently active topics in Google tagged with content

Okay before i begin, let me give you some background history. I run a very popular Wordpress powered blog called eGMCarTech (http://www.egmcartech.com. First my traffic had a sudden drop in January 2008 from Google. I finally got a hold of someone at Google and they told me that basically 50% of my content was not being indexed due to being on a shared server and that the server was blocking resources Google needed to crawl and index my site.

So I switched to MediaTemple (an amazing hosting company) on a dedicated server in end of April 2008. Moved my whole website there and started using a plugin called Google Sitemap XML (http://www.arnebrachhold.de/projects/...). Great plugin which creates a sitemap and pings Google every time you write a new post.

After that every article I wrote started showing up on Google within 20 mins. It was beautiful. Even my old content, which according to my Google Webmaster's account had over 2,000 pages with errors, got indexed and the errors went down to 128. Even my pagerank went from 4 to 5! I was having the time of my life.

Now here is the problem, starting May 12th of 2008, every article I've written is NOT showing up on Google. All of the sudden new content is not getting indexed. I made no major changes to the code besides using Disqus (disqus.com) as my new commenting system. I checked my Google Webmasters account and that says that Google last visited my site for a crawl on May 10th, and the number of errors went down from 128 to 58. I just checked Google Webmasters again and it says Google came by on the 13th. However none of my new content that I've written after May 12th is getting indexed! It used to get indexed like 20 mins after i wrote it and now its just not showing up at all. Not only that my old content seems to appear and disappear every now on then from Google.

Traffic is still stable and PageRank is still 5. robots.txt file is good and so is the sitemap.

Can someone PLEASE help?