I could be completely wrong, but I think it was explained to me that you when you have a 3102 disconnect, your ISP is actually still sending a signal to the game server. A 'cached' connection. So even if you aren't in the game, as long as the program is still running, your ISP is trying to keep you connected automatically. Thus shutting the game down and relaunching gets you back in quicker in most cases because it will force your character out of the game.