I rebooted, battery pulled while on, wiped cache and dalvik, reflashed stock 2.5...I think that's it. I was still receiving inbound texts, but when I would send one, the sending spinner (in HandCent) wouldn't stop. I texted 2 other cells in my house, neither received any of the messages. I even tried a 3rd number not on our plan, and they never got it. We were chatting over Facebook, so I know they never left my phone, despite being able to receive them immediately.