Help with sonic digital media

Hi all. I want to burn some cds. i went and bought some at the store, I go to make the disc, the first 2 out of the cds burned fine. then a few hours went by and now i get “please insert disc” error when there is a blank one already in there. its happeing with all of them now and dif brands too. I can still play the ones that I’ve already burned, it jsut wont make any new ones. help! thanks all.