has anyone had this problem with an external usb drive?

i just upgraded to 3.2 and everything works fine (primarily want to use it for booting off my external usb hard drive) except there is a distinct hissing sound in the audio when i play a video off the usb hard drive. not sure what could be the problem here, if anyone has any help that would be awesome, thanks.

Is this a video file or a DVD folder?