I have over 30 GB of music and counting in my library, and I wanted to put them in my iPod and then delete them from the library to save disk space.
I recall that I could do that simply in an older version of iTunes, as long as you didn't move the songs around in the iPod after you deleted them from the library.

Now, I can't do that anymore. So I check that box in Preferences which says that the iPod won't sync anymore, but it still syncs.

I then check another box so that the files can only be synced manually, but it still syncs when I plug in my iPod.

I then proceed to check yet another box that says only checked songs will be synced. I uncheck every single song in my library, but that son of a bitch still syncs them out of my iPod when I delete them.

So if anyone had this problem and managed to fix it, please tell me how, this is really frustrating.