im not sure if theres a reason for this, but when i get to the bottom of the stairs in the solar collection tower, my VATS refuse to work. which puts me at a major disadvantage against all the robot enemies down there. is this normal? im playing on the PS3.

PS3 here - I didn't have any problem with VATS when I worked my way through there.
I also had my BFF Boone with me, and ED-E, so that helped. I don't know if this is a spoiler or not so I'll hide it:



I hate to jinx myself, but so far the only real persistently annoying issue I've had with my game is being unable to complete the Screams of Brahmin quest in Novac. Got the target but the quest never updated, and he isn't respawning. Meh.

Many of us have it all the time. So, hopefully your problem will be limited to in the tower.