I have an iPhone that is cracked so that I can add ringtones and change the appearance of my main menu. I have version 1.0.2 on it now. Should I update my iPhone to the newest update? I have had 2 friends that did this and had horrible experiences and ended up selling their phones. They said that it would freeze up all the time. I want to update but do not want to ruin my phone. Any advise on this issue helps. Thanks!