Delisted by Google for keywords?

I am not completely sure of what is going on with my one site but I had noticed a drop in traffic. Upon further investigation it seems that my site has been delisted for keywords in which it was page 1 for google.

Articles I wrote that also ranked high (page 1-3) are still there so I'm still getting some traffic in a round about way, but my actual site that was ranking really well with google seems to slipped so far in ranking that it might as well be delisted.

I did search for site: www.mysite.com and I can see all the pages but it just seems that it's not ranking for any of the keywords. Weird, eh?

Most of my links are coming from article directories and I have some good articles...500-800 work real content. It is a review site so I don't know if this has anything to do with it but my stuff isn't really spammy...very low key.

I know that I had an issue with a social bookmarking plugin (this is a wordpress review site) and there were a bunch of 404 errors on my google webmaster tools page. I have since disabled the plugin.

I also have a "recommends" directory that I use 301 redirects to redirect to my affiliate links. I did set up my robots.txt file to not let google crawl that directory. But this has been like this for months.

I can still see google crawling my site but just wonder if or when I can expect google to give me some love back. I didn't go nuts building links. On a monthly basis I write about 20-30 articles and submit them to my blog that is attached to this site and then to 10 article directories. I don't do any social bookmarking and the site is about two years old.

Any thoughts or ideas? This is killing me! Should I just abandon the site and work on another one and see if it all straightens itself out or continue building links slowly? Any advice would be greatly appreciated.