I am tired of seeing the "You are not connected to the internet" message from iChat every time after I open my macbook. I use iChat for screen sharing. Is it possible to disable the annoying popup or should I just use another app for messaging and screen sharing?
You should probably use another app for screensharing and messaging. If you choose to do this, I reccomend Adium for messaging and TeamViewer for screensharing. I searched the contents of the whole iChat application, and I couldn't find anything, which leads me to believe that the pop up (I've had it too) is not actually part of the iChat application, but used by iChat.
Open ichat, close windows, logout. That fixed it for me.