Nexus 7 4.3 Reset akku time every new Start

[KWKF]

Hello,

each time i start my Google Nexus 7 with Android 4.3 the durationtime since last akku-loading is set to zero. ( shown in : Settings > Akku ).
Also in the graph the shut-off times are not marked as gaps.
After a couple of startings and / or sinking akku capacity voila, durationtime is okay, no resting after powerup the Tablett and the off-times are shown as gaps
Loading and using the battery is completly normal, battery itself seems to be okay.

Any suggestions ?

Thanks in advance ...

Klaus