[snovvman]

What apps have you installed? Do you happen to be using S2U2? If so, make sure that "Don't Suspend Power" = On. This is a known issue with S2U2 (search).

If you are not using S2U2, then look for some other app you installed that suspends the device before the native OS does.

If you are using a completely native/clean phone w/o any added apps, then I'd try a hard reset.

Good luck.