Hey guys I have a problem with my N900 (probably about 9 months old)

over the last few weeks the phone goes whacko and the screen turns off while you are trying to use it. you can fix this by sliding the "lock phone" switch.

except after 8 seconds (approx: dmesg shows when ive had to press the buttons again = 8.5seconds), you have to do it again! Have just reflashed "everything" (eMMC and the other image?), and have not restored any settings yet. The keyboard light stays on, and you can still hear the "click" of the touch screen if you press it (so I would guess the screen, is just off)

Is there a timeout in a config file somewhere, or should I just hope its covered under warranty?

Thanks!