Is the teensy even booting up then?
Since there are no pull-down resistors on the FETs, they may start in the "on" state when you power things on. This is normal, but as soon as the teensy boots it should turn the FETs off. In lightsaber-1.60.ino and later, this happens a few microseconds after boot. In older versions, it would happen 1-2 seconds after boot.