Why can't I sell two tickets to Neil Diamond?

I have two good tickets to a Neil Diamond concert at the AT&T Center in San Antonio for this Sunday evening, October 12, 2008. I can't use them and I've been unable to sell them. I've posted them on Craigslist and got nary a nibble. I've called all my peers to no avail. I know Ticketmaster is sold out. I wonder why no one wants these tickets. Nothing is as EZ as it should be!