Graphical glitches involving pistons

Pistons in this setup cause graphical glitches. Made of quartz, for one frame, one quartz becomes bricks. Also, a the bottom piston in the back turns transparent on the head for a frame. I cant get a screenshot because my computer is too fast for me to capture a frame
The design is a double extender by codecrafted.
http://www.youtube.com/watch?v=IP3Em1lcbrI