Liteon LDW-451S

I’ve recently installed a Liteon LDW-451S DVD writer and upgraded the firmware to GSB7.

I have no problem writing 2X DVD-RWs and can burn CDs (very!!!) slowly, however, have had no success writing DVD-Rs. Nero V5.5 and DVDCloner V2.02 both tell me that I have bad disks. I’m using Ritek G04s.

Any suggestions would be most welcome.