Right... my 770 did the same weirdness so i learned then to do the above and it still helps with my n800.

The above is a reliable and repeatable process which requires no deviation (like a lotta little presses). Is the above process something that wont reliably work for you?

I suspect all the issues are due to nokia trying to be smart and only 'sleeping?' when on ac instead of full powerdown when not on ac. You can tell because when it was just sleeping there is no progress bar during boot... its as if it just logged you off and logged back on. And i think when unplugged it goes into sleep and then 5 seconds later goes into deep sleep. I would recommend waiting the 5 seconds for full sleep to complete power mode sequence.

All the above are just my observations but i think thats the way it works (as glitchy as that is).