Red Rings again :(

I lost count already.

Got another Red Ring on my Xbox. :(

This time it started with COD5 where it would not save after the second chapter. Then it started freezing during the game. And finaly red rings of death.

If I desconnect it from the power, it comes back, but only let me browse in the menus.

I wonder if it is still under warranty, since I've send it back so many times. Also My receipt as a diferent serial number, because they exchanged it last time.