Yesterday at evening I fully charged my N900 and I have not used it since and now bam! - battery is on 40 %!.

There is no SIM in it, no data connections are active, bluetooth off, automatic Wi-Fi search off. There is Calendar Widget on the Home Scree + Date Today Widget, Nameday Widget and System Info Widget which shows 3-5 % CPU usage.

After restarting the device I see 17 % battery. Firmware is 1.3.
Any tips?