Most of you who jailbroke their iPhone 4 using JailbreakMe lost their MMS and FaceTime capability. I just found out about a fix thanks to Krapps and Branden3112.
To fix your MMS and FaceTime issue, simply follow these steps:
Go to Cydia and add this source: http://iphonedelivery.advinux.com/cydia/
Once this source has been added, install “iPhoneDelivery” from it.
Reboot your iPhone
Go to Settings > Phone > Turn FaceTime ON
Thanks Branden for the trick!
This is not an “official” fix from the Dev Team but I tried it myself and I can tell you it works. The Dev Team is still working on a fix that will most likely be available via Cydia.
If you use JailbreakMe now, you shouldn’t have any problem as it’s been updated to fix the issue. If you can’t wait for the official fix and if you don’t want to try this unofficial fix, you can always restore, and jailbreak again with the updated JailbreakMe.