I would try this, but before I do there's something that I need to be confident of... I currently have WAY more music on my iPhone than I have on my desktop. I'm concerned that if I do this process (i.e. uncheck Sync Music, then sync, then re-check Sync Music and re-sync), I will end up replacing the BIG inventory of music on my iPhone with the SMALL inventory of music on my desktop...
I`m using an iPhone 4S, with ios5.0.1, and havent had any problems for well over a year until yesterday, which was when I restored my iPhone from backup (which I had to do because ALL of my contacts had suddenly evaporated from my iPhone). Now I have my contacts back, but now I can`t hear 90% of the music that I had purchased through iTunes - it`s there, I can see it, but when I press Play, no sound comes out... Hundreds of songs are affected out of the 1800+ songs on the phone, so I`m not about to start tackling this problem song by song, nor album by album.
And I thought I`d finally gotten away from the big bad glitchy world of Bill Gates when I moved over to Apple...
HELP! I need to be SURE that whatever fix I try wont end up deleting the music on my iPhone... Thank you!