Users on the official Xbox forums are reporting 2 different colors of drive trays on the Xbox 360. The speculation is that freezing problems are occouring in consoles with an off white tray, while those that have a grey dvd tray are not having the issues. Thegame247 was having freezing issues, and sent his 360 off for repair, when it returned, he noticed that the drive tray was not the same as his original system. Coincidence, or drive issues?
Check out the post [here].