Mine forgets about 3 out of 4 times. May not seem like a big deal but when I tell you my usb port does not work so I have to charge externally it becomes a very big deal as I have to switch batteries everyday so I am having to reset time and date like everyday. I am also no longer able to use my N900 as my alarm. If I change battery at night before I go to bed I do not switch it on so do not know at that time whether it has reset the date and time.

I have tried to determine whether there is a trick to the 1 out of 4 it works. Do I leave battery in for a minute after switching off before taking it out? Do I wait a minute to put in new battery? Do I do everything superfast before the device realises what has happened? I can't find the answer. Seems totally random.

Don't know when the problem started. Until my usb port became faulty I did not really have much reason to remove the battery.