What I expected to happen was...:
similar outcome on all cases.

What actually happened was...:
the first outcome is not the same as two, three, four, etc.

Steps to Reproduce:
1. Place a dropper/hopper and run it through a quick redstone pulse
2. Check the outcome after the first time and check again all other times
3. Notice a difference that the first one caused not compared to any other case
4. this video explains it fairly well...
http://youtu.be/8bJoajlhhGc