Same experience here - once it's fixed it's fine. Mine had a TON of plays and after it was initially fixed was fine for the entire time it was on location (now getting fixed up since the subway fell apart)
Quoted from sd_tom:
ok so beyond the 'fix' with the zip tie.. other things i did (just looked at my emails with barry)
this mounting situation on the big pcb is not ideal.. especially the power pins (the bottom left area). i think in addition to what i wrote to barry, i eventually very carefully unplugged the p-roc from the main pcb and very slightly bent the power pins so they had better contact with the receiver end when the board was plugged in. but you have to be very careful to not bend the pins when unplugging it since theres a lot of pins / pulling the board off evenly is challenging.
and yeah, make sure some gorilla didn't overtighten any of the boards so they are now bowing.
good news is ive never had to go back in there and do it again or had p-roc not found errors