Jeff- yes, it was actually when I was removing the battery to check the country of manufacture that I noticed it - I tried to use the power button to turn it off first but nothing doing. So I removed the battery anyway and then noticed it wouldn't turn back on.

penguinbait - above probably explains it; it's easier to turn something off than on ;-)

I have actually got it back on, I think simply through multiple pressing of the button (for around five minutes.) Pressing button now, even multiple times, fails to bring up the 'turn off' menu.

This is a very recent development, off button was working earlier in the week. Current plan (as I am going away on holiday) is to avoid turning it off until I get back and return it then (it is rare that I turn it off.) But I will of course recharge fully etc. and see if this helps. Can't reflash obviously if the on button no longer works!

Edit: One of the main reasons this annoys me is that it means I can't use my spare battery on the transatlantic flight and thus get two movies out of the thing. I guess I am resigned to whatever crap they are showing this month.