I've had a situation in the past where the lock screen ring didn't work. It moved a tiny bit and then feel back down. In my case, the phone hadn't gone into password mode so I was able to pull down on the status bar, drill into settings, and disable/enable the screen lock again.
What you describe sounds different when you mention an all white screen with only status bar. When sense reloads you get the white screen with HTC logo, is that logo on your screen?