OK I bought 2 Copies of BF3 + Karkland via Origin (one under my username one under my brothers.)

i've had no issues,

however,

My Brother, when going through the campaign, his teammates/AI sometimes do not spawn, or about 5 minutes into the mission the spawn.

(ie the DIMA Mission where they are driving in the day to that garage, the car drives itself, no AI Teammates what-so-ever.)
in the final mission in the final sequence, the Bad guy didnt spawn (left out spoilers), he ended up just fighting an invisible button timing combo.. lol.)

also online in COOP, he starts the mission, he can see bullets and the environment being damaged, but no enemies, im on my PC telling him theres about 30 running up to us and he see's nothing.


Is this a known glitch?

his System

Win7HP 64Bit
AMD 6850 Cat 12.3 (i think).
4GB of Ram.
PhenomII 555