Okay, so I'm trying to implement a nav list with the button images being drawn from one singular image. When the user mouses over I want the image to change from the top 34px to the bottom 34px, please help me with this. My website is www.blindpuppetry.com and its a work in progress. Please help me with just this.

Thanks

Your website doesnt seem very functional yet. The links aren't clickable or anything.

But heres an example using one image to act like two images for a button, I think this is what you wanted.

http://radgh.com/test/

Ok,what you are describing is called 'sliding doors' and there is a TON of information on how to do it on the web:
Part 1 - http://www.alistapart.com/articles/slidingdoors/
Part 2 - http://www.alistapart.com/articles/slidingdoors2/