I will assume you used the image below:

If so then recheck your wiring to the footswitch and be sure there are no cold solder joints and re-flow if needed.
Popping sounds are not the result of this PCB (since we use a pull-down resistor 1M) but could be switch related and there are a plethora of other possible reasons aside from that. You can Google and find several pages full of tips regarding pedal pop. Here is a Good One.
That said since it could be a multitude of things we would need great pics to possibly see if it is something related to the off-board wiring. Be sure to test the pedal (with no other pedals) and with only 2 known good cables and nothing else.