The first thing you need to do is make sure the backlight is not set to Always On. To check this, pull up the Settings menu on the iPod and scroll down to Backlight Timer. Ideally, this should be set to 2 Seconds for audio playback, though you'll probably want it set to Always On for video playback. The next thing you need to check is the click-wheel. If you're using a silicone case, it's possible that the hole for the click-wheel might be off-center, and the edge of the case might be registering a touch on the click-wheel. If this is the case, it will constantly read a control input and keep refreshing the backlight timer countdown (unless it's set to Always Off), thus keeping the backlight on at all times unless it is forced into Sleep Mode (since the registered input will keep it from timing out and putting itself to sleep). All you'd need to do to prevent this is recenter the case around the click-wheel so you don't see any major gaps around the edge. And finally, after you've plugged in the iPod, you can always force it into Sleep Mode manually by pressing and holding the Pause button (doing this will not actually put it into true Sleep Mode, as it will immediately switch over to the charging screen), or let it time out by sliding the lock button. Once you've done that, the only two things that will wake it up are pressing one of the five control buttons (simply scrolling the click-wheel will have no effect) while it's unlocked, or unplugging it.