After I have done the iOS 6 upgrade last night, I just could not send SMS from my iPad via tethering. The strange thing is, I still could surf websites and everything else. Only sending SMS does not work anymore! I also like to mention that if I am using the iPad via WIFI connection, iMessage on my iPad works fine, and SMSes on all my 3 devices (iMac, iPad and iPhone) are synced together with no issues. Anyone here encountering this same problem as well? I have been trying to troubleshoot it the whole day, but to no avail.