[Mark McLeod]

I just pointed that out because it's an obvious error. Use of the Set instead of the Get is causing extra work, because it keeps replacing the Refnum entry 50 times a second for Joystick 3. I don't know what grief that might be causing elsewhere, but I suppose it could be suffering from a propagation delay. At the least it's probably wiping out the Joystick cache.

For debugging you can run Test mode from the Driver Station to see if all the devices show up on the Dashboard Test tab, and from there you can test each of them by clicking on "value", then using the control that appears at the bottom of the Test tab. That'll bypass the Joystick to remove it from consideration (or point to it as the culprit).
P.S.
You can also watch the Joystick buttons being pressed, so you can be sure the Joystick is working normally.

BTW, the button operating the solenoid should light a status LED on the Solenoid Breakout if it's working. You don't need the pneumatic system to see if that's responding properly.