I disagree about LiteOn being crap burners. Crap media even on good burners like Plextor/NEC also leads to DVD movies skipping occasionally like every 20 mins, unusable coasters after few years.
Actually if u buy decent quality media LiteOn can burn dvds with very low PIF/PI errors. I copy alot of DVDS and always perfect burns when using TDK and Verbatim DataLife+, while had problems when i was using generic media made in China.
Have u tried using a program that tests your copied DVD's for PI and PIF errors? Like Nero CD-DVD Speed program, goto Extra in menu and select Quality Test. Even original DVD's u buy from shop have some PI and PIF errors though few. All DVD drives/players have some error tolerance so dvd viewing never skips appears perfect.
Club CD Freaks forum has really good articles on good DVD media.
DVD Media Tests
If you read their articles u will never ever buy generic media again. I mean like 40c each for generic media that occasionally give coasters and you have to throw away, 60c each for good branded media that always give perfect burns NEVER ANY COASTERS like Taiyo Yuden, Mitsubishi, Ritek.