The solution, mentioned by forum user stlcardinal9sr is as follows:
In the XMB delete your game save data and game data utility for Black Ops, all of your online stats will still be there, you will lose single player stats though, I decided to check this and found that the patch actually loaded into game save data and not where it should have in GAME DATA UTILITY…After deleting and redownloading everything works like it should!!!!
Steps to do this:
1. in the XMB under games where you would click on the disk to load black ops scroll up to where it says saved data utility.
2. delete this data, what will happen is you will lose all of your campaign progress and on your custom classes you will lose whatever you have named them but all of your classes will be the same and no online progress will be lost. just rename them
3. scroll up a little more to game data utility and click it and delete the black ops data, you will NOT lose any online progress.
4. now go reload the game up and it will require you to redownload the patch and you should be up and running.
We were not able to personally test this at RipTen – but we emailed the solution to readers who said it fixed most of the issues immediately.
*The solution is not perfect but will fix the patch for the user who corrected it. If the host of the match has not corrected this problem you can still have issues. The more people who correct this, the less issues people will have.
Note: This is not an authorized solution given by Treyarch