Songs titles from CD not showing up

yesterday when i put in a CD all of the song titles and artists and album names and all that stuff was showing up fine but now all of a sudden it isnt. When i go to advanced and click on get cd track names it says "CDDB error. HTTP processing error." someone else said "Make sure that any firewall is set to allow connections to gracenote.com and iTunes should pick up all the artist, album and track information automatically." but im dumb when it comes to computers and i dont know what that means! please help!