You will have to forgive me my computer skills are not the best. I have happily been burning cd-r for about a 2 months using cd-r's i have copied films and audio i ahve had no problems until today. my optiarc dvd rw ad-7170s has decided it no longer likes this type of disc, it plays original DVD's & Films copied on to DVD-RW's no problem. it will not play any CD-R or original Audio CD's. I am using Nero 7 and it just say's that there is no media disc inserted i have downloaded copyxdvd that has made no diference. the only technical message i can get is "buffer underrun protection activated" but i don't know what this means? can any one help?????