I have experienced many sites which have been penalized, the firt thing to check is does your domain rank with out the .com bit, and yours does, most will have -10 -20 -30 -40 -50 penalty. A large redesign will cause you to drop out of the serps while Google looks at all your pages and tries to confirm the overall theme. Much empahsis is played on site content and internal links, if lots of these change then the age of those links have been lost and need time to recalculate. Have you changed the names of your pages as well? This will have a huge impact if so. It will correct it self, make sure using webmaster tools that all external and internal links go to pages that exists and if they dont redirect them to ones that do, its a great way to get those links back and working in your favour.
I had the same problem some weeks ago after I've changed a lot of things. Google "filtered" me for about a week and after that the site came back to his previous position in serp.
well you are still index in google and also you have pr 3 on your home page so its mean you didn't get banned from google. but yeah maybe you lost some of your back links and serp ranking in search engines , i suggest you to wait for one or two weak to came back your site in search result because its normal that site get disappear from search result just for some time specially it happen alot with google
ya, my site was not in first place for the domain belmos..... i am in 4th place,,, i think the site redesign created the problem, i am going to wait to see how it goes