I do not think you did. Just came back from vacation and used tethering frequently. Didn't show up on my bill at all! However, I had the SAME problem you did.
It's an easy fix. Follow these directions before hooking up.
1. Click on
Internet Sharing.
2. Click on
Menu.
3. Click on
Connection Settings.
4. Click on the
Advanced tab.
5. Click on the
Select Networks button.
6. Make sure that both networks are
SPRINT. If the second one it
My Work Network, change it to
SPRINT.
7. Click
OK.
8. Click
OK.
Now you are ready to connect your USB cable and you are good to go. I have no idea why it reverts to the Work Network, but once I change it to Sprint, it works. It will have to be done everytime you use tethering, though.
Hope this helps.
Maybe someone has a quicker fix, though
.
Regards,
MG