For anyone that is still searching for solutions to the PCI slot problems let me clarify what wojtas is saying.
I have a P8P67 Pro Rev 3.1 2600K and X-Fi PCI extreme gamer 2 x GTX 465's BIOS 2001 latest Intel Chipset Drivers
I disabled the support for all USB 3 devices.
Advanced>Serial Port Configuration>Enabled>IO=2F8h; IRQ=3
IRQ settings enable and disable PCI settings amongst other port settings.
This confguration enabled me to download the Creative Beta Driver .
I then enabled all the USB 3 support.
My Creative PCI card now works along with all my other hardware.
The sound is noticeably superior to the on board sound so keep plugging.
There are issues with some of the other Sound Blaster applications but that is a whole other story.
I am using different versions of Vista, XP and Windows 7 the only program I still cannot get up is the Volume Control Panel.
However this should work for some of you.
Remember why we do this. We like mucking about with hardware and software
Edited by Pitcairne - 12/4/11 at 12:30pm