Problem with GPIO push button inputs following Pypilot upgrade

[drbarritt]

Hi, I have recently upgraded Pypilot on my RPi3 to 0.24 so that the OpenCPN Pypilot plugin will work.  Everything seems to work fine (including the plugin) except for the push button controls I have connected to the Pi GPIO.  I checked in hat.conf and the GPIO definitions are all correct.  when I browse to port 33333 I get the remote control setup web page and this shows it is connected to Pypilot, but the button presses are not showing. 
Any ideas as to what I may have missed during the upgrade?
Many thanks
David