Been thinking about this, knowing the players you play and having played with you. I cant help but suspect part of your problem is that you know these guys are so bad you keep chasing your losses, even though you have a stoploss. What about taking up a version of Fnords approach? Once you're down 2 buyins you try to win 1 back. If you drop one more (or even half a buying) THEN you quit. Kind of gives you permission to chase your losses a little bit, but still with a saftey net for quitting?