The small bug was that i saw a small glitch with the visuals.
i made a clock and ran redstone diagonal to a piston. i put another piston over it facing sideways. the top piston had the block selected but it was slightly behing it. see the first pic. next was an old bug where the piston was powered but it looked like it had 2 heads.
Environment
Put your operating system (Windows 7, Windows XP, OSX) and Java version if you know it here
Duplicate of MC-127 and MC-1677, please use the search function to see if your bug has already been submitted. Currently over 57% of tickets are being resolved as duplicate.