When going into The End the obsidian pad (and three blocks above it) will regenerate everytime the user enters The End, this will provide an unlimited amount of obsidian. I have made a video on this bug here - http://www.youtube.com/watch?v=G3sIXg-AF0Q&noredirect=1

*What I expected to happen was when I renter The End, i would expect the pad to not regenerate.

*What actually happened was the pad would always regenerate, this would provide an unlimited amount of obsidian

Steps to Reproduce:
1. Enter the end
2. break the pad
3. leave the end through the portal
4. enter the end again
5. break the pad again
6. repeat from step 3