Windows 8 randomly disconnects from Wifi (WPA2 TKIP/AES)

Good Day,

Our issue: Windows 8 & 8.1 Laptops randomly disconnects from our Wifi infrastructure (WPA2 TKIP/AES)

- We make use of different hardware for Wifi infrastructure, mostly Ruckus (with Zone Director), but also NetGear, Cisco and Ubiquity.
- New Windows 8.x Laptops as well as older ones that we have reloaded (Win 7 Pro reloaded with Win 8.1) does the same, the moment there's Windows 8.x on the Laptops the would randomly show "unable to connect to Wifi" and one would have to disable/enable Wifi, or in some cases reboot the Laptops before they would connect to Wifi and work for a few hours before disconnecting again.
- We've disabled all power management for the Wifi Adaptors (windows can't shut them down to save power etc. etc.)

-  We make use of WPA2 with TKIP/AES algorithms (I've tried both, and now placed the AP settings on "auto", problem still persists...)

Does anyone know if there's perhaps an incompatibility with Windows 8.x and WPA2 or something else that is causing this phenomenon?

Thanks for any assistance.

Reinhard.