Hi there, first post here so please bear with me. I am a recent convert from Windows to Mac and I am running a mid 2010 Mac Mini with El Capitan 10.11.2 and iTunes 126.96.36.199. Before I upgraded the mac mini from Snow Leopard, I moved my iTunes library across from my windows laptop via a home workgroup connection, and imported it into iTunes on the mac. I did this because I didn't want to have to download every song I've ever bought from the iTunes cloud again, only to have to go through and delete the ones I don't want anymore. I then upgraded to El Capitan and began the process of associating my iPhone and iPad with my 'new' iTunes library on the mac. Since then, I have checked/ticked the songs I wish to listen to/copy to my iPhone and unchecked/unticked the songs I do not wish to listen to/copy to my iPhone at present. If I close down iTunes properly, then reopen iTunes, I find that within seconds it has re-checked/re-ticked songs I previously unchecked and having had a few goes now, it annoyingly does the same thing every time I restart iTunes, whether I've synced with my iPhone or not. I've tried a system re-boot too to no avail. As a non-expert, my guess is that there maybe some sort of config file I've copied across with the iTunes library from the PC that could be causing this, but I have no idea where to start and I'm otherwise at a complete loss with this. I'd really appreciate anyone's ideas of things I could try to sort this out. A search on this subject has yielded no relevant results. Many thanks in advance, ATR72.