This is driving me utterly insane and I can see no reason for it happening. Take an album - any album. I-Tunes seems can't seem to decide if its a single album (and therefore have a single cover) or multiple tracks all with individual covers. So, I highlight them all, get info, and apply a uniform set of information across them all and say "yes" to compilation album. Now, sometimes it works, sometimes it doesn't. Going through track by track confirms that they all have identical album, artist etc, and the comilation is ticked. Yet I-tunes still refuses to accept it as a single album. WHY!!! Does i-tunes get confused with bigger libraries? Currently sat with 130Gb of tunes.