I have a iPhone 4 with iOS 3.4.4 (I just tried a JB last night so it was too late to use 3.4.3, I had no blobs saved) and everything works fine except when the iOS is installed an the phone restarts it won't finish the boot. It is stuck on the black screen with a silver apple logo and the circle loading symbol is stuck on about 3/4 complete. Help please.