I have noticed that connecting to online games of Call of Duty: Black Ops on my PlayStation 3 have been painful. Every patch seemed to make it worse. Long story short the PS3 connection issues may finally be fixed as Treyarch has released a hotfix to address connectivity issues.
I have had issues with the xbox 360 version of the game as well, but not nearly as bad as the PS3 version. Hope there is a patch for the xbox 360 version as well.