822 is the buggiest OS I have ever used, buggy on the 8520, and even crappier on the 9000, ringtones become silent all of a sudden, lock key doesn't function properly, etc, many bugs and RIM has even publicly announced it!
Install
5.0.0.771 it's the best! very stable, good battery life, and good reception quality with almost no memory leaks and fast performance.