From searching and reading, I've gathered some things that I'm hoping someone can verify for me.
Are the following true statements?
1) The Phillips DVD in the XBox cannot read CD-RW, CD-R, or DVD+RW, and some cheaper DVD media "out of the box"
2) It is possible to "tweak" the drive (by strengthening the laser) to read the CD formats.
3) The CD laser tweak will also allow you to properly read (or at least make better) the DVD media
4) If you replace your DVD drive with a standard PC drive, it will not be capable of reading XBox original.
There are just my observations, based upon the various forum postings.