Epson stylus photo R300 cd/dvd tray not set correctly
I had the same problem. Restarted the printer. Reinstalled the drivers. Scratched my head ... nothing! then I moved the printer away from the wall - problem solved! I can't say that this will work for you but if everything else is working, as it was and still is on mine then it's worth a try.
What I didn't realsie was that the cd tray comes out of the back of the printer when it's checking the alignment. I had inadvertantly pushed the printer back, too close to the wall. Moved it forward slightly and it's fixed.
Hope that solves it for everyone.