"Data Call Failure - Error code 67."
Explanation: Some users are getting this error while tethering (tethering essentially turns your android cell
phone into a Wi-Fi hotsport).. Sometimes this error means that your Cellular data username/password is incorrect (for
providers that make your phone authenticate besides just having the correct APN name entered).
If you call the cellular providers about this error, they will have you do the usual.. reboot the phone, turn it off,
take the battery out, pray, put the battery back in and boot.. Usually won't fix the issue..
Make sure your internet sharing button is also turned off.. (unchecked) when connecting/tethering to your PC via USB..
Widgets or programs running in the background trying ot make the data connections aggrevate this problems (HTC weather
updater keep trying to update for example).
Roaming (moving to different cellular zones/providers) can also cause this error to.. If a cell tower isn't configured
correctly (cellular provider most likely misconfigured to allow you to roam onto their network), you might fail the
'authentication' and receive this error..