Ships Will Not Attack Planet

well, i can't find where to change strats other than when making a ship to produce. i tried telling them to only target or fire on just the planet but its always the same, they just make a bee line at it, bank off and swirl around while getting pounded.

i just tried making a ship with nothing but CS missiles and that worked kinda. it at least started shooting at it but still, what gives? if they did something like making some weapons not usable for assualting a planet then make it known =/

EDIT: tried it on the stock game with patch and it seems that no matter what i do, my ships will not shoot a planet with the DU: cannon (normal or mini) i havent tried the other weapons besides the CS missile so.. yeah =/

is this normal? is there a setting or list so i can at least check what weapons will and wont work when i'm trying to take on a planet?