Couldn't work out how to "shoot" but have now managed to...
If for example I'm using "Keyboard Layout B (Cursor keys, Right CTRL and ALT = Fire)"; when you start and press Right CTRL it will accelerate the ship. If you then press Right ALT it will shoot
Thing is I don't seem to be able to shoot and accelerate... Anyway; guess this is one of the bugs or I possibly need to use a 2 button joystick / joypad?