I've had an 8 GB Nano 4G for a couple of days. It has the most current firmware version. I've had to reset it twice so far to fix the following: In the first day of use, it became very sluggish in responding to button presses, especially after reorienting from vertical to horizontal and back. In the second day of use, it became completely unresponsive after completing playback of an album. The Nano wasn't being moved during playback, so the accelerometer wasn't involved. The screen was totally blank and it didn't respond to any button press. In both cases, the battery was fully charged, and the reset took care of the problem. What I don't know is whether this is a firmware issue or a hardware issue, like a memory problem. Anyone else seen behavior like this?