I've got a 3GS running on 3.0.1. Previously I installed PDAnet then I uninstalled it. I then installed sinfuls mms and tethering package. Well the problem starts when I put in the following info for my network settings.
I reboot and then go to network settings and tethering goes away when I try to turn it on. I can only get tethering back when I reset my network settings. I JB'd my cousins phone and his keeps both mms and tethering. he has the same software and phone only difference is I run itunes 9. and he runs itunes 8