iPod Ipod Nano 3g Click Wheel working abruptly

Hi guys. New to this forum. Bought my nano 3g about a month ago and occasionally the click wheel stops responding completely. The only way to restore function is to lock the device and unlock. It happens intermittently. On the latest firmware which i've downloaded and installed twice. Should I return my nano for an exchange?

No I don't think you understood what I meant. If I'm using my device normally, all of a sudden the menu will stop responding. the only way to get the device to work is to hold and unhold. Anyone else having similar problems?