This is a tough time to feel as if you have a penalty, because Google is churning a lot right now... perhaps in preface to an update. That's my guess, but it is a guess. I wouldn't make any onsite changes at the moment.
First, what makes you think, apart from this online diagnosis, that this is specifically a minus thirty penalty? Take a look at the
Hot Topics [webmasterworld.com] section, pinned to the top of the Google SEO forum home page, and look at the articles in the penalties section.
From what you've said about your site, what jumps out at me is the possibility that the links from your articles in various article directories and those that have been syndicated might be looked upon as some sort of spammy link building arrangement. If the articles dupe content that you also use on your site, that could be creating difficulties for you.
all my 1st and 2nd pages have been moved back to the 5th or beyond
Counting on my fingers, this sounds more like -50. I'm not sure how absolute Google is these days about how many pages down your penalty should go, assuming you have one.
Check out the penalites section, but take a look at this article in particular...
Help with Minus 50 Penalty - December 2009 http://www.webmasterworld.com/google/4046016.htm [webmasterworld.com]
It is the kind of thing that could be a Google error, as well. Look into that, but check your site first to make sure it's really clean.