Apple wireless keyboard and instant wake

[kenstu]

If I have a Apple wireless keyboard connectet via BT, sleep only lasts 2 seconds.

No problems with other BT devices (speaker).
No problems with USB sticks and USB HDD.

How to solve?

 

[kenstu]

If I boot the OSX system on z87n-wifi, I have the sleep problem.
Booted on z87-HD3 with a usb-bluetooth-stick, everything works with sleep and even wake from sleep via bt-keyboard.

so problem is:
the wifi/bt card of the z87n,
or a bios/uefi -bug in the z87n.
or a usb - bt card problem on the z87n

I could get the answer , if I remove the wifi/bt card and check with the bt-usb-stick.