If you're thinking of buying one of these..... don't.
This is the first time I've ever reviewed anything, but I hope by doing so I'll save someone else the headache I've had with this product.
The first one that arrived simply failed to work - admittedly it was replaced quickly which was the last time anything associated with this product went smoothly. The second one suffered the same faults as you'll read in other reviews - it randomly turned itself off within a minute of switching it on - and then turned itself back on (which is nice). Thereafter it stayed on until switched off as you'd hope. However, it then started to switch itself on for no damned good reason, more than once in the middle of the night - and these things aren't quiet! Trying to get this second unit sorted has been painful, the supplier passing me to Samsung who then passed me to Amazon who then passed me to the supplier who then...... you get the idea. It's currently been returned for repair which apparently can take up to eight weeks - nice touch!! Samsung were completely unhelpful to the point of being useless - they were unable to find an invoice emailed to them by the supplier and claimed that it hadn't been sent, they failed to return a phone call within a sensible amount of time. As I say, if you're thinking of buying one of these - just don't.
Update: Unit number three has also failed (rewind button acts as a previous chapter button, the picture quality is badly compromised when fast forwarded or (due to faulty rewind button) previous chapter is used) it was collected today (6th Feb 2012)-we'll see what happens, though I've asked (not unreasonably in my opinion) for my money back.