Ive gotten about 3 DDE's(dirty disk errors) from my Xbox since Xmas.
2 were from my friends halo disk, which was dirty and scratched up so I know why it did it.
The other was about 2 weeks ago with my PDO game, which is in PERFECT condition, a simple reset fixed the problem.
I do have a 3 year warrantee, so if the thing decides to act up.. I'll just get a new one.