The whole QC-Piston thing is based on a bug. I don't know why they don't fix the old pistons and add 2 new Pistons that work with QC.
I can't believe that this is intended. Back in version Beta 1.7 the pistons worked fine. With this behavior it is nearly impossible to build small piston contraptions, without glitching as hell. R.I.P. pistons.
The whole QC-Piston thing is based on a bug. I don't know why they don't fix the old pistons and add 2 new Pistons that work with QC.