I move about a lot so I don't use a joystick and when I use the keyboard, the guns don't work when I manoeuvre with the arrow keys. The mouse sometimes works, but then sometimes it only rolls the fighter.
It sounds like a key rollover issue. With the exception of some high end gaming keyboards, modern keyboards can only recognize so many simultaneous keypresses. If you don't have a laptop andthere is any way to connect your keyboard to the old school ps2 (round) port, it may work better