ok I am typing this on my phone btw. Ok I can't get into great detail right now but the reason macs running on os 10.5.8 or anything lower is having this problem is because os 10.5.8 and lower are on lepeord and only support up to Open Gl 2.0 mine craft is asking for 3.0 or higher because of the 1.8 update. the method that I am doing right now to fix this is upgrading to Snow leopard which is 30$ or a free torrent and booting it of a flash drive. I will report back when my Mac is done istalling snow leopard.