It's probably the CD tray. One way to get round it is to give the tray a nudge when it's supposed to start as the rollers are not pulling it in. Mine does the same but the nudge does fix it.
Brian, May 2008
It could be that the rear of the printer is too close to a wall/obstruction. I had this with mine It needs about 6 inches behind the printer for the tray to side in and out - I moved it forward and it worked fine. Hope this helps
