After updating to 6.1, my iphone 5 would constantly ask me for my Apple ID password. It will ask about 4-5 times and then finally stop. I thought all was fine, however when I went into settings, I noticed that my e-mail address (apple ID) was not selected as an address for imessage. Only my phone number was listed. When I choose to add the e-mail as an address to be reached at, it goes through the same process of asking for my password over and over again until it finally just removes my e-mail. Has anyone else experienced this issue and/or found a way to fix it? Thanks in advance for your help.