Quoted from PinMonk:The very annoying sound popping problem in versions 1.9x is a real problem for location play unless the machine can be rebooted daily. JJP is shooting themselves in the foot on this, and it's been an issue for like 4-5 months.
I think JJP mentioned that they may have an option to have the machine reboot daily to help. I think the new software build is 'close' to being made available.