I'm not shocked, those graphs include cash given to churches and stuff. Money given to the cause of god should not be counted... god doesn't need money (he's got really good credit).
In all seriousness though, that's why those states are so high above. The churches take contributions from the poorest families in the name of god. They collect the contributions through moral guilt, which is an excellent way to get paid, but shouldn't really count towards generousity charts. Sure the people are generous, but they are god fearing and fear kind of counters out generousity.