It should be able to recognize the drive even if the formatting is wrong. If you're positive you got the connection right, it could be a bad drive (I've had DOA drives before.) Is there another enclosure you can stick the drive in to test it? You can get universal connectors for about $10, like this:
http://eshop.macsales.com/search/universal+drive+adapter
It's a pretty handy thing to have around anyway.