Problem With Network Internet Conection

Hi All, Im on an internet conection, I plug my network card into a network port in the wall.

Ever since I got here, My interenet has had many problems:

1) Every so often server not found messages will be displayed for 30-60 seconds before the internet works again.
2) At the same time, MSN, Xfire, and anything else will sign out, and not let me sign back in for the 30-60 seconds.
3) If im playing a game during this I experience a huge lagspike, Sometimes making me lose the game, sometimes making me lose conection to it.
4) I Cannot download anything, The download will get so far then my internet will go funny and it will just say sat at whatever, The only way around this is using a download manager, but many sites do not support this, E.G Im unable to get the latest BF2142 Demo!

I Have tried the second network socket on my PC, and the results are the same, I have replaced my network cable, I have done a rollback of my PC.

Im realy at a loss as to the cause of this, But having talked to someone else on the same conection (In my apartment) They have no problems at all, they can download, they can stay conected, they never get server not found messages......

Please please someone help me!

Thanks, Jcb33