Then I'd try the standard workarounds:

1. Add an app/bookmark then delete it.
2. Reduce brightness, mine's next to minimum and I'm comfortable with it.
3. Might be wrong, but some say deleting and then creating again an account helps.
4. Reflash? (it's drastic, but tbh my N9 started acting like a smartphone only after 2 NSU and 2 Phoenix reflashes )

Your mA values are way too high, I get 220 mA when playing pocketRPG for a few hours, but that's heavy on cpu/gpu.