I have an iPhone 4 and my girlfriend has an iPad 2. When trying to add songs wifi to her iPad to our iMac a couple days ago, iTunes decided to uncheck all of her synced playlists essentially taking off all of her music. To make matters worse, it also just decided to add every single app (most of which were my old iPhone apps from when I used to sync to that computer) to her iPad. I wasn't there, and thought maybe she clicked something incorrectly. Fast forward to last night. I simply wanted to add two movies to my iPhone from my MBP. iTunes proceeded to remove and reinstall certain songs (over 1000 I believe) at random. The sync took almost 2 hours with a wired connection. Lately I've noticed that everytime I sync my phone iTunes will remove and reinstall songs. Why is this? I haven't changed any track information in my library. This morning, I noticed my custom alarm ringtone didn't play and when I checked, all of my ringtones had been removed. Grrr! I plugged my phone back to my MBP and watched as iTunes removed over half of my music, leaving the greyed-out husks of the tracks. Grrr x 2! I've scoured the boards here and abroad and found nothing to explain this. If anyone has any suggestions/advice, I'd really appreciate it.