I had no issues performing the upgrade from the downloaded file. I did not need to change the file extension.
The only thing with the update for me is that it only updated the TX file and left the MX file alone.
My question to others is did your MX portion change with the update?
If you will be purchasing ANY AT&T services online or in store could you mention that you were referred by me? My Employee Referral ID is eo4489. This would be a great help and it costs you nothing, thank you!