USB audio interface losing playback with GenericUSBXHCI installed

Hi,

I am using the latest build of Clover with 10.9.5 on an Asus X99 Deluxe board. I've installed GenericUSBXHCI.kext 1.2.7 because I was told it was necessary for Fusion to load my Windows virtual machine. Without it, Windows would never finish booting - something about a very high number of interrupts, I believe.

However, with that kext installed, my USB audio interface (a Scarlett 2i2 which uses Coreaudio) loses audio output. iTunes or any audio application will still be 'playing,' but the audio will simply cut out. To fix it I have to unplug the audio interface and plug it back in again, at which point the issue will occur again, seemingly random. I've looked through the Console output but there's nothing that would point to the issue.

If I remove the kext, I have full USB3.0 speeds, but then of course I can't launch my virtual machine. Any help? I have some USB options in the BIOS, but I'm not sure if any of them would be helpful.