extechop, I understand exactly what you're saying and I'm not sure why some others aren't getting it and being slightly hostile.

I guess technically in this aspect the N900 is working correctly according to the specification, as the wording on the tickbox matches the perceived behaviour. What you're asking for (and I agree) is for a different setting, a tickbox for "Display stays lit while connected to charger". This tickbox could replace the existing one, and the behaviour in the background modified to match the wording.

Anyone interested in this could vote for https://bugs.maemo.org/show_bug.cgi?id=10496 although I wouldn't hold out too much hope for this being fixed in Maemo 5. I don't know what the MeeGo behaviour is - does anyone know?