For anyone who has had their visual voicemail broken since the 3.1 update try this solution. I do not know if this will work outside of AT&T.
So the problem seems to be that if you installed the hacked ipcc file (either through help.benm.at or manually uploading the file through iTunes) and then updated to 3.1, not only would the 3.1 update disable the tethering/mms, but it would also corrupt the carrier file, therefore breaking visual voicemail. I have tried every method out there including resetting the network settings, removing Profile settings, restoring my iPhone (seven restores including a downgrade to 3.0) as well as spent more than four hours on the phone with AT&T and Apple but to no avail. Here is what finally worked for me. And for those interested, this was done on my iPhone 3GS 3.1OS.
1. Perform a system restore on your iPhone.
2. After the restore, choose the option to setup as a NEW iPhone.
3. Perform a “Restore from Backup…” in iTunes (in iTunes, right click on your iPhone and select Restore from Backup…)
4. Open safari on your iPhone and navigate to http://help.benm.at/generator.php
5. Enter wap.cingular in the APN field for both Mobile Internet and Visual Voicemail. Leave the rest of the fields BLANK and click GENERATE!.
6. When the Install Profile page opens, click Install and the then Install Now on the confirmation warning.
7. After it finished install, go back to your home screen.
8. Perform a HARD RESET by holding down the Lock and Menu buttons (power and home buttons)until the iPhone reboots and the Apple logo appears on the screen.
2. After the restore, choose the option to setup as a NEW iPhone.
3. Perform a “Restore from Backup…” in iTunes (in iTunes, right click on your iPhone and select Restore from Backup…)
4. Open safari on your iPhone and navigate to http://help.benm.at/generator.php
5. Enter wap.cingular in the APN field for both Mobile Internet and Visual Voicemail. Leave the rest of the fields BLANK and click GENERATE!.
6. When the Install Profile page opens, click Install and the then Install Now on the confirmation warning.
7. After it finished install, go back to your home screen.
8. Perform a HARD RESET by holding down the Lock and Menu buttons (power and home buttons)until the iPhone reboots and the Apple logo appears on the screen.
You should now have visual voicemail AND mms working on your 3.1 updated iPhone! I understand the frustration of the whole process and sincerely hope this works for you!




