usually it does read ..
if it's not your writing as a process on the DVD blank was bad , or DVD blank was bad..
Well lately my MK-4 stoped to read DVD's ( even original DVD OEM disk) ..so as today it does read only CD's and cd-r , but as CD format only ..I do not have any dissent explanetion why..but think there was a dead battery story in the past and after that it's beahaving this way..