Carths Son Side Quest & Sand People Turrents

[darth pwnage]

Okay.. here goes
On Tatooine where you go into the sand people's umm area and you attack any one of the sand people then when you go to the door the turents automatically attack you. Well, my first time in I got bye with the uniforms and made my way through... but then was killed by the chieftain..
But when i came back with the uniforms on, i got ambushed and my party attacked all the sand people the saw outside of the enclave. So I killed them all off and went to go face the turents, but i could not damage them no matter what force power i used or grenade... well, now that i think about it i had two thermal detonators and destroyed one turent but when i threw them at the others nothing happened. This sets me back and i have yet to see the star map. In all my times playing this game, this has never happened.. what should i do?
And also, if you go through and kill everyone in the sith academy can you not start the side quest for carths son? It makes sense that you couldnt, but i just wanted to make sure..

thanks
oh, and who thinks Naga Sadow owns? I DO! haha