What would cause a clunking noise when going over bumps

I have a 2010 Mazda 3 iSport Sedan (~20,000 miles) that makes a clunking/popping noise from the front passenger side. The noise occurs when going straight or when making right turns but only when going over a bump/uneven road. It does not occur every time the car runs over a bump though. I also notice more vibration from the front when going around 50mph. I took it to the Dealer a few weeks ago because it is still under warranty but they were unable to find anything wrong. I was able to capture the noise on video. Thank you for your help!

http://www.youtube.com/watch?v=I7qqLzQWMdg