Close the game

Browse into wherever you installed the game. Program files, steam, steam apps, common, call of duty black ops, players.

Rename your config_mp file to config_mpbak, then launch the game. This will reset your config_mp file to stock.

You will need to redo your Player tag, and remap your keys. Classes wont change, although you may have to rename those. The class names arent sticking yet anyway.

If your results are improved, you can always delete the new config_mp file and name the original back to config_mp.

This has helped a bunch of players have a smoother game....