Why won certain DVDs play in my DVD player?
DVD-ROM is a data format (like CDi and CD-ROM). What you think of as “DVDs” aren’t DVD-ROM format. Not true. A video DVD uses the same on-disc format (UDF) as a data DVD; it just has a specific set of files stored on it that contain the video and menu data. This is different to the situation with CDs, where audio CDs use a different on-disc format (Red Book audio) to data CDs (ISO9660). So it won’t play DVD-ROM disks but it will play DVDs. I’m confused. Saying that the player supports MP3 CDs but not CD-ROMs makes equally little sense. I suspect what they were trying to say is just that the player can’t do anything useful with CD-ROMs that don’t contain any MP3s, or with DVD-ROMs that don’t contain video data.
“So it won’t play DVD-ROM disks but it will play DVDs. I’m confused.” DVD-ROM is a data format (like CDi and CD-ROM). What you think of as “DVDs” aren’t DVD-ROM format. “For the life of me I can’t get DVDs to play in it….a DVD of “Dawn of The Dead”… started right up.” These kinds of drive mechanisms are usually pretty crap quality, but generally speaking if it won’t play “a DVD” it’s because the DVD is a DVDR on crummy media, the title is too copy-protected to actually work well on crappy embedded hardware, or the drive is marginal.