the letters have got nothing to do with the drives themselves... it's only an assigned symbol to represent and access the actual hardware. and it could be set up wrong. Some drives could be bitchy if you put them in a slave slot and use have set it as a master from the jumpers or the other way around. But I'd think that it would make the drive not work all together rather than just fucking up dvd-play.
I know...I could change the names if I wanted to as well...I'm just saying that to differentiate between the two, because one drive is CD/DVD burning (E Drive) and the other drive is specifically a DVD Burner and has LightScribe abilities...basically they're the same though, I just realized today the E drive can burn DVDs as well so there's not much of a difference.