I've recently moved house, and we've just got the internet up and running. At my old house, Ghosts worked fine, but since i tried playing it here online, it won't work. I try opening a standard multiplayer game, it goes to the serve, but then won't load the game. The loading icon still moves but none of the controller buttons work except the "PS" button. My internet connection is good (as i've tested it on other games) so there is something wrong with ghosts. Sorry for the long paragraph but any help would be GREATLY appreciated. Thanks.
I'm guessing you have not configured your router or PS3 for optimum connection.
If your in-game NAT is not Open then you will have trouble.
Give the following link a read:
Forget that your other games play fine. You want to have Ghosts set up correctly. This will also improve your connectivity in all other games.