Affects Version/s: Minecraft 1.4.7
Fix Version/s: None
Environment:Put your operating system (Windows 7, Windows XP, OSX) and Java version if you know it here
Put the summary of the bug you're having here
What I expected to happen was...:
Describe what you thought should happen here
I made a semi-auto sugar cane farm and it works.
What actually happened was...:
Describe what happened here
for some reason the top 4 pistons create a fake extended piston block.
Steps to Reproduce:
1. make what is in the attached screenshot and press a button that will invert the inverted signal