Have a Sony DRU 510A. Bought some 'Melody' brand dvd-r from local shop. First 2 worked fine. Then the Veritas RecordNow software started rejecting disks. Have since tried Datawrite Classic (Yellow) and TDK and no joy. Tried firmware update to 1.0f, since Sony support says this improves writing reliability - but an attempt by the machine to write anything would now be very much appreciated! Any useful comments?