Call of Duty: Black Ops has just received a new patch. The update is focused on improving performance, particularly on systems with dual or quad core CPUs. CPU performance is supposed to be the issue behind the stuttering that many players have been experiencing when trying to play online, so if you've been experiencing those issues, this update will hopefully solve them. The patch also includes a "Friends fix for join in progress and Friends tab in server browser". Steam will apply the patch automatically the next time you start up the game.