I just recently installed the new 660 ti and a new 850w PSU into my system, and ever since whenever i get done gaming for about an hour or more, and decide to shut down, my computer makes an odd almost squeak noise through the audio right as its shutting off. Does anyone know what could be causeing this? I've been having no problems with audio performance while the computer is in use whatsoever, it's only when i power down...