Norton internet 2009 preventing sing in on my computer

This is my first post today i installed norton security to find out what this firewall can do, and learn how to use it, so my problem is i cant sing in with messenger, i have no idea why, i tried to read some instructions from help guide but all i did is to find windows messenger and change from auto to allow in case i can sing in this way, but still i cant sing in even with the allow option.