Scott, I did a quick search and come up with this
http://forum.ppcgeeks.com/showthread.php?t=115051. But as you note, this has been answered in several diff threads and there are a few fixes, one you tried didn't work, maybe the other ones will... Or post in those threads and see what others on the stock 6.5 can help you with. I can't offer you any other recommendation as I'm on a custom ROM that has stealth tethering... IMO that's the safest and best way to go.