imessage won't log me in
Usually when I turn my computer on or open it back up & log in, iMessage will automatically log me in and show my buddy list. For some reason, sometimes it won't & whatever I try to do (like change my status from offline to available) will not work. I have tried restarting iMessage multiple times & still it won't work. What can I do??
MacBook Pro, iOS 5.1.1