ASUS M5A97 USB Disconnection problem

Okay, I am posting here as I am making an assumption that it is probably something to do with my motherboard, or possibly win 8.1. 

My problem is to do with the rear USB ports on my motherboard, which is the ASUS M5A97. I have found that after a period of time (which can vary), my USB devices plugged into the motherboard will suddenly power down, well, the ports seem to power down as they become totally unusable until I restart my PC, I have looked up this issue online but found nothing other than a setting in windows 8.1 that powers down USB ports after inactivity, but its always my keyboard, mouse, and WiFi dongle that are affected, and only happens at all when the WiFi dongle is plugged into the rear USB ports on the board itself, if the WiFi dongle is in a front USB port, then I get no disconnections or powering down of ports, so after changing my USB settings to get rid of this power saving mode, I am still stuck with this problem and has only started happening since I upgraded to windows 8.1, (previously Win 7)

The USB WiFi adapter I am using is the ASUS USB N53:

Any input or assistance would be greatly appreciated, this problem is really driving me to distraction, especially whilst trying to complete work and having to restart when I haven't saved in a while. 

Thanks in advance, 

update the bios to the latest version. Bios version 2501 Enhance compatibility with some USB devices.

And download and install, the latest usb 3.0 driver from the asus site.