Hi everyone, I did do some testing with turning off my DR800SG vs leaving the last page I was reading displayed and simply locking the device. Turning it off makes a big difference to how quickly the battery drains. Even turning it off the iRex doesn't last anywhere near as long as my Sony PRS505 does but it is acceptable. Leaving it turned on is completely unacceptable. I was normally locking the device and leaving the page I was currently reading displayed. I am guessing that it is the clock that is draining the power although I don't know this for a fact.
I will turn my iRex off as a workaround for now...............Jackie