Maybe 6 weeks ago I set up new "goals" in analytics for a client with a corporate (they are a franchisee) subdomain, which is a horrific mess. That fact slipped my mind (the goal, as pathetic as it is was 2.2 pageviews per visitor), and when I check analytics today I saw what I thought was a spectacular month in conversions from AdWords. A bit more digging made me realize that wasn't the case, but that now my "goals" in analytics included the new settings (oops).
While goals in GA and conversions in AdWords can overlap, the differences are key. As a Google rep explained to me: you can set and import goals from analytics into AdWords, but not the other way around. So structure and exact definitions are important.
More info on the differences between Google Analytics and AdWords tracking