Black Ops received its first PC patch. The game had been suffering from lag in multiplayer as well as performance problems but should now be that much better for PC players.
Steam reported the update in their news section, saying major changes included:
- Friends fix for join in progress and Friends tab in server browser
- Performance improvement for dual and quad core systems
This patch is for the multiplayer part of the game (multiplayer and single player are divided into two separate games within Steam), but CallofDuty.com has a more specific change list which leads you to think there are fixes for the solo player version, as well.