my dru-810a burner wasn't burning correctly for a while as well. the only media it would burn correcty for videos are verbatims. i upgraded the firmware to 1.0e and it still didn't fix it and i was kind of running out of ideas until i decided to remove my nero 7, cleaned all the registry files and folders in program and common files folder and installed the Nero that came with the Burner. From then on, i could burn dvd movies on media brands like, ritek, maxell(cmc), hp(phillips), verbatim and etc... try it and see if it'll fix it then if you want to stick with nero7, remove the old version and clean everything again before installing the latest version. also, upgrade your burner's firmware.