Is anyone else having trouble engaging in battle with guards? I can lock onto a guard, but when I hit X to draw my weapon nothing happens. I don't recall having this problem with Assassin's Creed I and II. I'm having the same problem with the Revelations as well. I bought Brotherhood via XBox Live so I initially thought that was the reason. I decided to buy the Revelations game disc and assumed the problem would go away. The only way I'm able to kill my enemies is to grab them each individually and slit their throat. It's obviously a little annoying, but thankfully I'm able to compete memory. I assume there's nothing to be done, but I'm just curious to see if anyone else is having the same problem.