Firstly a big thank you to aekritzinger for being one of the first pioneers to resolve this type of problem, you are a legend! (hope you get to read this)
Second, to Orange FR, I just pwned your "experts" big time, as their only response was restore its original settings and forget about your backup, start from scratch.
I have an iPhone 4S iOS 5.0.1 & I encountered this error from an update Orange did to their APN Carrier Settings, when I tried to access the internet I received the following error.
I was not able access the profile section in the general settings as specified in their instructions
Orange's support was limited and only offered basic resolutions. Thanks to aekritzinger post https://discussions.apple.com/thread/3462255?start=0&tstart=0 and the following tools; ibackupbot for iTunes & plist editor Pro I was able to find the solution.
1. Use ibackupBot for iTunes to find the file SystemConfiguration/preferences.plist in your recent backup which corresponds to the file 8218978e4ab0a48035bb92653145a6be872ea858
2. Export this file including backup information (this is very important if you wish to reimport your modified file afterwards) to a temporary directory.
3. Copy the file 8218978e4ab0a48035bb92653145a6be872ea858 to a temporary directory. (in case of restore issues - you never know)
4. Move you old backups which live here C:\Users\%USER%\AppData\Roaming\Apple Computer\MobileSync\Backup to a temporary directory.
5. Restore your iPhone to its original settings. (don't sync as of yet)
6. Verify that everthing is working after the restore: 3G/VVM/MMS
7. Backup your iPhone
8. Use IbackupBot for iTunes to find the file SystemConfiguration/preferences.plist in this new backup which corresponds to the file 8218978e4ab0a48035bb92653145a6be872ea858
9. Export this file including backup information (this is very important if you wish to reimport your modified file afterwards) to another temporary directory.
10. Open this exported xml file with Plist Editor Pro.
11. Copy the entire contents.
12. Open the bad exported xml file with Plist Editor Pro (2.)
13. Paste and replace the entire conents of the file.
14. Save the modified XML file
15. Move the new backup which is in C:\Users\%USER%\AppData\Roaming\Apple Computer\MobileSync\Backup (7.) to a temporary directory. or if you don't won't it for any future use, just delete it.
16. Move you old backups which are in the temporary directory (4.) back to C:\Users\%USER%\AppData\Roaming\Apple Computer\MobileSync\Backup
17. Use ibackupBot for iTunes to import the modified XML file (14.) into your recent backup (1.)
18. Restore from this Backup in iTunes to your iPhone.
19. Verify that everthing is working after the restore: 3G/VVM/MMS
20. Sync your apps and music etc..
21. Bob's your Uncle! (without loosing any of your personel data as your operator insists must happen!!)
Initally I tried to compare the two plist files and modify/remove entries to match the orginal file so I could keep the <key> references the same as I don't know if they are referenced in other plist files, however this did not work afer restoring from backup.
Interesting to note is the two additional line entries for each DeviceName entry. IP1, IP2, IP3 IP4 in my plist.
For more details on the differences in the files read my reply in this discussion.
Hope this helps people stuck with issues with their APN Configuration on iOS 5