Weird Nav button problem …

Hey guys, i ran into a bug with my my header navigation that i cant figure out. Basically the nav works perfectly fine here:
http://wearefuckingawesome.org/site

but when i add the www in front of it, all of the buttons fail to work …
http://www.wearefuckingawesome.org/site/

im testing this on a mac – safari and firefox.

I have no idea why this is happening. Any ideas??