in PR 1.1, when the "ear" sensor was covered (as in I placed my N9 into the leather case, so can't see the clock anyway anymore), my N9 would the smart thing - it would turn the stand by clock on the black screen OFF

in P.R 1.2 it does switch if off at all

Maybe the consumption of the clock is minimal, but it was the principle I enjoyed owning a SMART phone