I have an ATT 8525 (HTC) and lately, it's been freezing up. At first, when I'd take out the battery and put it back, the phone would work fine again. Now, it won't even turn on. A lot of times, I'll leave it charging all night, and in the morning, it's frozen and won't turn on, and if it does, it says the battery is almost dead. Does this sound like a problem with the battery, or the phone itself? I'd bring it to ATT but it's an unlocked phone and I'm afraid they wouldn't help me because I'm not an ATT customer. Any help is appreciated!