I have a recording studio with several 32 bit audio drivers
. Usually not a problem to have 32 bit devices or drivers in Win 7 64 bit.
I would suspect a problem with the sound card more than the drivers. PCI suggests old hardware. The motherboard you have is a new board and the PCI sockets on most new boards of this type are actually "bridged" from the PCIe bus and not a true PCI slot. This can cause problems with some PCI devices.