My Xbox is being kinda weird and i dont no y?

Your's makes 4 (iirc) complaints of the same problem I've seen here on YA in the last couple days. Some even tried on other machines, still no read, got replacements and still no read. Sounding like there was a batch of bad discs. Good luck finding a replacement that works. When you go to the store to exchange it see if you can try it there first on one of their demo consoles if they have them set up. Save yourself another return trip or ten.