Tested with hopper with 64 coal and 64 raw chicken.

*What I expected to happen was:

The hopper would move the coal and chicken into the oven.

*What actually happened was:

The hopper moved the coal, but not the chicken.

*Steps to reproduce:

1. Place a hopper on top of an oven
2. Put some oven fuel into and raw food/ores/cobblestone into the hopper
3. The chicken does not move to the oven.

(However, the roast chicken WAS moved when I put a hopper below the oven)