I have a Smart Playlist set up which has all the songs I have purchased through iTunes using their "free song of the week" promotion. I've been downloading these songs for a long time, so some of the songs are protected AAC audio files, others are purchased AAC audio files. Right now, this playlist has 147 songs in it. I'm running iTunes 10.5.1 on Lion 10.7.2, and have iOS 5.0.1 installed on my iPhone 4. I sync my music automatically in iTunes, and have this playlist checked to sync to my iPhone. However, on my iPhone, this playlist only has 115 songs in it. Of the 32 songs which do not get transferred to this playlist, 1 is a protected AAC, the other 31 are purchased AAC files. 25 of them are of the last 26 songs I purchased, but the oldest one goes back to May 2008. If I make a new playlist which has only these songs in it, and try to sync this playlist to my iPhone, it syncs as usual, but the smart playlist does not update to show these tracks. I've tried resyncing my iPhone, and, for an unrelated reason, had to do a full reset and restore, yet this issue has still persisted. Does anyone have any idea of what might be causing this, and how to fix it?