Why was I Dropped from SERPS?

Google no longer indexing my site

[BallochBD]

Forgive me if this has been covered before but I am quite new to this and at my wit's end with this latest Google update. I need all the help I can get. My main role is as a consultant in another discipline but I do have some IT background and I have created and promoted (what used to be!), a successful, information based website with 80 pages. This has received many plaudits from within my industry and I have built up in excess of fifty links. I offer lots of free information and white papers.

I was severely damaged by Florida and during the last couple of weeks, killed by Austin. Here are the facts. A couple of weeks ago Google started dropping some of my pages and they are now almost all gone. They are still in the index but show nothing in the cache. Doing a "site:www.mysite.com" tells me that all the pages are still in the index, I think? Apart from two exceptions the list of pages shows only the page name, i.e. there is no page title or cache information.

My site still shows its original PR of 5 but on occasion this drops to 3 then reverts back to 5. I am also listed in DMOZ. I have some other domain names for different sites sitting on the same hosting space (same IP address) and these are still being indexed regularly.

After Florida I keenly started researching SEO and discovered the excellent Webmasterworld. I became an avid reader and applied some of the learnings to my site. I had used some keyword techniques on my site for two years without a problem (well after all, Google actually tells us to "use the words that people may use to search for us".)

However Florida forced me into a rethink and I completely "cleaned up" my site. As far as I can see there is nothing in there that would get me a penalty. I will also admit to using similar SEO techniques on all of the sites but none of these has been dropped. In a nutshell it appears as though the clean up has caused the penalty although this may just be coincidence. I emailed Google about this a few days ago but all I have so far is a standard acknowledgement and I don't hold out much hope of getting anything else. I would be very grateful for any assistance.