iTunes: Songs Not Checked in Library Copied to iPod Anyway
Songs that are checked in a playlist but unchecked in the Library are copied to the iPod when the "Only update Checked songs" option is selected.
Symptom
The "Only update checked songs" option in the iPod Preferences window is selected, but songs that are not checked in the Library are copied to the iPod anyway.
Solution
Make sure the songs are not checked in any normal or smart playlist.