ELH #115 - Parallax Effect

I've been working on the ELH#115 challenge and have gotten my parallax effect to sort of work. I'm hoping that someone might be able to assist me or point me in the right direction.

I am trying to create something similar to this effect incorporating both videos and images. http://whiteboard.is/

I've reviewed many of the samples and I thought I understood it, but it's still not working quite right. I've gotten things to move, but it is not working the way I intended. Any tips or help on how to fix it would be appreciated. My third graphic (Paramedicine-Slider) is not sliding in smoothly. The second graphic (Trades-Slider) is working as intended.