Two daisy chained 74HC165: Can’t detect several button presses at once

Using Arduino LEDs and Multiplexing
14

Okay, there is now only one problem: One button changes the bit in the first byte even if it is connected to the second 74hc165 ( =second byte) and the button that should change the bit in the first byte isn't changing the bit at all.
this seems to be a shiftIn() problem… Why?
I tried this code and it hasn't this problem: Arduino Playground - ShiftRegSN74HC165N

Edit: Okay it's a common problem between the 165 and the ShiftIn function. Including an
digitalWrite(clockPin, HIGH);
before setting the latchPin LOW solves it.