Your wireless connection might be an issue. If you can try using a wired connection to see if maybe this makes a difference. I have seen problems with wireless connections such as not being able to connect to the game server, or constantly disconnecting (due to dropped "packets" or pieces of information wireless is notorious for).
Norton 360 has also caused issues with some games I have played in the past (such as not letting you connect to the game server. Next action if you can't switch to a cabled connection, is to see if maybe Norton 360 is stopping you from connecting to the server (as I seen this in another game I was playing). See if you can disable Norton 360 modules via this article