Maximum PC

I'll give you guys my symptoms and hopefully you guys can point me in the right direction. This is for the PC I built back in March and these 2 issues were not issues right away but have been nagging me for a few months now.

Hardware:
MoBo: ASUS P8Z68-V/GEN3
Ram: Corsair Vengeance 16GB PC12800 DDR3 1600MHz
PSU: Corsair Professional Series HX 850W
CPU: i7-2600K (Corsair Hydro H80 CPU Liquid Cooler)
GPU: EVGA GeForce GTX 570 2.5GB
KB&M: Corsair M60 & Corsair K60

Issues:
1. Random Resets. My computer will randomly just restart, as if the power has been cut off. The computer reboots immediately and works just fine like usual. This will happen anywhere from 1-4 times a day. I figured this could be my PSU, but maybe its my Mobo because of issue #2.

2. My Mouse and Keyboard will will lose power randomly. Both peripherals will loose power at the same time. They are connected to to the USB ports in the back. But I have even hooked them up to the USB ports in the front of my case too. It's like the MOBO doesn't want to power my devices anymore. We all know with out mouse and keyboard we can't do anything. So I have to restart my computer when this happens. Then they work fine again... until they will randomly lose power again. I even try unplugging them and hooking them back up and tried using the ports in the front. But that's a nogo, so I have to restart. This can happen 1-3 times a day also.

I just ordered a powered USB Hub to see if this helps with my issue #2. However, there is obviously something not working right. I would think that my PSU is bad since my PC restarts randomly. But the issues with USB ports makes me think, maybe my MOBO is bad.

I of course have all the BIOS/Firmware and drivers updated on all my PC parts. I had all these issues before I overclocked my computer, I monitor my temperatures and they are always fine. Right now just using the browser my CPU is 23 degrees Celsius and my MoBO is 27 degrees.

What is odd, when I'm playing games my KB and Mouse have never lost power (yet). It dosn't matter what I'm doing, using normal programs like a Photoshop or a browser or playing video games, my PC will reset whenever it feels like it. So the power load on the PSU has no effect on when it restarts. Thankfully with my SSD my computer boots up in a few seconds, nonetheless, it is frustrating when either of these problems occur.