Do you have the pneumatics breakout wired and supplied with 12v? Do you see an LED lit on it?
http://www.usfirst.org/sites/default...20Breakout.pdf
When you activate your joystick button, does one of the lights on the NI 9472 change state?
If not, I'd look for errors on your dashboard, especially anything about an unknown device ref.
I might also try setting your solenoid on with a true constant, verify that works as expected, if it doesn't, you've got something wrong with the solenoid code, or the hardware of the pneumatics pieces.
You can always place a breakpoint and probe in the teleop code, and see what's what, are there any errors on the error outs, do you see the joystick button changing states as expected.