I have an iPhone 4 (iOS 5.1). I have tried to sync it multiple times and it claims it has finished, but some of the songs are not syncing. All the boxes are checked and I have even tried to drag and drop under manual management. I have 378 songs in my library, but only 362 on my iPhone. Not all of them are transferring and it's getting very frustrating. I am also having a problem of two (or more) of the same albums showing up on my phone even though, in my library, everything is grouped correctly. Please, help?