I know this thread is old, but I had a slightly different problem to Centerfold, and hope this reply might be of use to someone.
I'm not tidy; my trash was overlowing, and "Empty Trash" just wouldn't work, whatever I tried. I could delete individual items, but there were SO many it was a nightmare.
I noticed that right at the bottom of my Trash bin was a copy of the Library folder (how did it get there? No idea). I couldn't delete it, move it, nothing. It dawned on me at this point that maybe I couldn't empty trash because the Library folder is deemed essential.
What I was able to do thou