UPDATE - turned the IT off cause I didnt have my cell phone charger and it didn't turn on right away every time. What I said below does not apply to the problem.
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disclaimer - I have no idea if what I did and solving the power on/off enigma are related.

My N810 had this problem until I performed the operating system update. Now it turns on every time. This update to OS2008 has to be done in red-pill mode.

I used to be afraid to turn it off as it would not power up immediately but now does every time.

MY OS is still OS2008 vers 2.2007.50-2