From skimming some other threads it looks like some other people may be having a similar problem, but I couldn't find a dedicated thread. My Hero occasionally will do a factory reset for what appears to be like no reason at all. In the first three weeks I had the phone it happened about four times. All settings gone, everything wiped except the content on the SD card. Huge pain reconfiguring everything. After the first time I started paying more attention to try to diagnose the issue. I noticed that this always happens when I am powering the phone back up after having been charging (and once it boots, it goes back to the "Welcome to your new Hero!" screen to input your google login info). Furthermore, it only happens when the phone fully runs out of batteries before I start charging it. At least two of the times I have noticed that before properly booting, it shows a warning display (a little picture of the phone with an exclamation mark sign behind it. like the icon for this thread!). Maybe did I try powering it back up before it had enough battery? Running out of batteries, charging, and then booting up seemed like too common a series of events to be "part of the phone", so I figured the phone was defected. I was still in my first 30 days of having the phone so they let me exchange it for a new one with no hassle. Now, on a whole new phone. Same thing happened yesterday. So it's got to be something I'm doing. I don't use very many Apps. Just last.fm. SD card has some images and mp3 albums on it. I'm stumped!!!