Was introduced with "the redstone update"

A powered block in a row only powers a piston directly above it or to the side of it but powers a 3 by 3 cross beneth it. The powered piston beneth the powered block seems buggy as the pistons around it will not update if the piston is removed whilst powered and the powered block as well. se pictures. The files with JAVAW in the name were takning in the order of their timestamps to show the bug when removing the power.

Discovered while writing this.have two block on top of each other and pistons going out around the bottom block will permanently power the pistons if the bottom block is removed. See http://gfycat.com/VariableLateAphid