SE let us know that failing to use "/shutdown" could cause a rare instance of our 360 being unable to read the FFXI disk (problems with FFXI + NXE).
Turns out, even using /shutdown can cause your xbox to stop reading it, since sometimes FFXI fails to shutdown properly on its own, going to a black screen instead of the dashboard.
Well this happened to me. I bought the NEW Vanadiel Ultimate Collection, still didn't work. I just bought a new 120GB harddrive and copied my old drive over, still didn't work. Seems the only solution was to format your drive and lose ALL your saves/demos/arcadegames etc (since FFXI can't be removed from Xbox dashboard, only from the POL disk and in this case the POL disk won't load.
Then I stumbled up on this gem:
GameSpot Forums - Final Fantasy XI - fix to disc read error!!!!! works for real!!!!! (ipod required)
But the funniest part.... it actually works. It doesn't have to be gangster rap.... but just plug in an iPod/PSP/Mp3 player/Flashdrive (maybe just playing music from your xbox harddrive will work as well).1. hook ipod up to your xbox360
2. download codec or whatever its called so that your 360 will play aac format songs
3. play gangster rap music from your ipod through the xbox 360 from THE DASHBOARD (i only tested it with gangster rap but feel free to try anything please let us know if other genres work)
4. with gangster rap now playing proceed to put your ffxi dvd into the drive
5. log in and party up!!!!!
While the MP3 is playing, load Playonline and low and behold, it works. 175 dollars later trying to replace my hardware (needed to be done anyways) and all I had to do was listen to some Dr Dre.
Go figure.
Hope this helps.