Facebook Open Graph Description Issues

Hi,

I've set up the Facebook plugin on a single WP install. The custom site description appears properly in the Open Graph tags in the page source code. Yet, when someone clicks the Like button, the description shows up as "Just Another WordPress Site." I don't even use that on the site...I've replaced it in the WP settings. So where is this description coming from?

I heard something about OG using the default if you don't have an excerpt, but I'm not sure where I'd put an excerpt to represent the whole site.

Thanks,

Mark