Each post from my blog have in description this "5 Feb 2008 ... Archives. September 2008 · August 2008 · July 2008 · June 2008 · May 2008 · April 2008 · March 2008 · February 2008 · January 2008 ..." "22 Feb 2008 ... Archives. September 2008 · August 2008 · July 2008 · June 2008 · May 2008 · April 2008 · March 2008 · February 2008 · January 2008 ..." Take a look here
I think it is because your first H2 tag is the "Archives" one and misleads GoogleBot thinking that it's your site content below it. Try changing the tag to a class insted.
LeoT is on the spot. Change the H2 tag and make it div. Also, make the header h1. Insert the header and a little code snippte in the meta description field.
What's your URL like? It's either missing a description tag, or your description tag for your template is set up incorrectly.
you definitly don't have titles and descriptions... that's the problem tags have nothing to do with this.