I'm also running 2.2.1 with Baseband version 62.50SJ.20.17U_188.8.131.52 and Kernel version 184.108.40.206-27237-gbe746fb android-build@apa26 #1 and Build number FRG83D.
If I select Wireless and Networking I see Airplane mode, Wi-Fi, Wi-Fi settings, Bluetooth, Bluetooth settings, Tethering, VPN settings, and Mobile networks in that order. If I select Tethering I see USB tethering and Help.
I hope that helps. Have you tried connecting your phone to your computer with the USB cable and then looking again at settings. I don't know that that would make a difference, but it is worth trying.