Hoppers doens't work properly

I was trying to make an automatic sorting system like this on
(http://www.youtube.com/watch?v=GEHytKwXfDE)
But the hopper wont take on any new items unless the hopper is directed towards the hopper below.
The priority of the hopper has changed to the hopper on side instead of the hopper below.

If you make the same sorter in 1.7.2 and then in 13w49a they will act differently