Door Bug (with the redstone block)

What I expected to happen was...:
I would put a redstone block next to a door and above a block, then the door would open.
(I know what i tried is not usefull, because the redstone block blocks the door, but maybe this bug could happen with other objects)

What actually happened was...:
The door (iron and wooden one) do not open (with the redstone block above other block), although the door opens with a redstone torch above a block.

Steps to Reproduce:
1. Put a door (wooden or iron one);
2. Put any block in front of it;
3. Put a redstone block above the block which is in front of the door.