Help, caching problems on repeat view

Hello,

we have recently implemented amazon cloudfront CDN on our website and things work fine except that the test is now showing that we have caching problems on repeat view. http://www.webpagetest.org/result/120821_J5_DFF/1/details/cached/
Can somebody please shed some light on why this could be happening?

Thanks a lot!

There are no caching headers on your static content: http://www.webpagetest.org/result/120821_J5_DFF/1/details/#request2

Is your origin server emitting cache-control or expires headers? If so then maybe this: http://stackoverflow.com/questions/10049366/cloudfront-cache-control-headers-missing