I was at a part in the storyline that involved me fighting a bunch of Securitrons, and they seemed completely dumbfounded as to how to get at me while I stood behind a couch and shot at them, picking them off one by one as they just stood and stared at me. I could walk right up to a lone one and it would shoot at me like once every 15 seconds. This was on Normal difficulty.

Yep, AI and enemy glitches in this game are really too frequent. Literally a third of the scorpions I fight are stuck in the ground.

What platform are you on? I'm on PC and I've seen a handful, but not nearly that many, maybe it's a specific glitch? I have seen plenty of enemies just stop shooting and stand there though, it made some parts of the game fairly trivial in fact (the bunker isn't hard when the paladin just stand there after all, they're just power-armored loot pinatas then).

I lured two Freeside Thugs to the gate to the Strip, the Securitrons probably spent a good minute getting one of them to half health before I got bored and left. One of the scuritions was just randomly shooting missiles down the road, it seemed.

360

Hmm, perhaps RobCo only gave them basic AI or maybe they were running WIndows Vista?

HEHE this reminds me of when I first met a deathclaw , I saw ed-e shooting at something I turn around and its 2 small death claw(my height). we kill those, I walk away and I hear veronica say watch it.

I turn to see a big deathclaw running at us. Next thing I know it disappears. It fell through the ground. Ed-e is still shooting at it while its under the ground. I keep moving around, but to no avail. KOed with one hit from under ground.