How do I fix this iTunes problem?

Mabye you got your password wrong or something I would google it

Run Disk Utility—> Repair Permissions.

Yeah, disk utility, definitely.

So I did the verify permissions and repair permissions, but it still doesn’t work. Should I back up and re-install iTunes?

I’d try simply try de-authorizing your computer, reboot, authorize again.

Maybe that’ll do the trick

One question, does your iTunes library reside on an external drive?

My iTunes is backed up on an external drive.

One thing that I forgot to tell you is that I just got an iPhone. I had an iPod touch and I gave it to my brother, which he used on his computer with his own iTunes account. When I tried transferring apps that were backed up to iTunes onto my iPhone, they didn’t work. Could this be information of value?

any news?

I emailed iTunes support and they said to delete the folder SCINFO. I searched in spotlight, but I can’t find it. I replied to Apple and showed them some screenshots. Hopefully I’ll get a response soon.

What is SCINFO? Where can it be found?

Did you ever get a solution to this? I’m having the exact same problem (may 7, 2010), having migrated my itunes from old power book, to rental macbook, to new macbook pro. Fully one third of my nearly 3000 iTunes songs are inaccessible!