Falling into a falling sand entity

What I did was attempt to run through falling sand entities.

What happened was that I fell down along with the entities and once the bottom entity became solid, I remained partially suspended in the top block.

To give a visual explanation I have made this video: http://www.youtube.com/watch?v=OHuMfRa7j6c

What I expected to happen was to fall down fully and suffocate to death