Hard reset erases preferences sometimes?
Usually a hard reset (holding home+lock for about 10 seconds) results in an apple logo boot screen and then the phone coming back. Sometimes, though, the apple logo will have a progress bar underneath it. When this appears, many of my preferences are blown away (all sound prefs, battery percentage) and Siri will reset back to it's first use state. Anybody else experience this?
iPhone 4S, iOS 5.0.1