Sorry my first post may have sounded like the ramblings of a mad man - im was frustrated as hell
1. The Tower is using the standard prismatic beam - it works on most occasions (90% of the time) . Its only loses the target every now and then and start firing again , so i can confirm it is chanelling .
2.The Tower attacks ground units fine and attacks air units , i have air units which i've changed the movement plane to ground , but the damage from this tower still doesnt seem to affect them even tho the attack happens .