Okay, So I just thought I would post this as I want to completely reverse my Jailbreak of my iPhone 4 because I lost my ability to Facetime and also I want to keep my warranty intact. So if someone could just read the steps I took and confirm that I have removed all traces of the Jailbreak with the data from my iPhone that would be great. It was my fault and I thought it would be cool to try it out with a friend and I'm no hacker or anything and just want my iPhone to be completely clean of the jailbreak so Apple or O2 doesn't find out. 1) I connected my iPhone to the computer. 2) I open preferences, went to Devices and deleted all my backup's. 3) I then turned my iPhone off and held the power and home button for 10 seconds and then released the power button until my computer said installing Apple DFU Mode. 4) iTunes prompted that iPhone was in Recovery Mode and I hit restore. 5) After the restore I set a new name for the phone (As there was no backups) and synced my Apps to the phone, I also updated the carrier settings again. Also while I was in Cydia it prompted me to do something which I accepted, I read on the internet that it is Firmware Signature Caching or something simular. Is this going to affect my iPhone in anyway now that the Jailbreak is removed? Also I installed some themes, so now that I have done all the steps to remove the Jailbreak I suppose they have been removed completely from my iPhone and shouldn't affect my iPhone in any way. Thanks.