Getting instantly disconnecting when trying to log into the realm

Wanted to see what the frostwolf server was like i downloaded it and i got in the first try but i had restarted the game to install some addons and then i couldnt get back in it justs disconnects me as soon as i log in i checked the config notepad file to check for the SET realmlist "logon.warmane.com" it wasnt there so i put it in and still does the same thing can anyone shed some light on this.

fixed: found out that keeping the optimize net work for speed lets me go in turning it off doesnt let me connect

Something that should be stickied in my opinion. Someone needs to make a list of possible errors and sticky the topic to keep new players informed.