Bring up properties for the SMbus device in question, click the "Details" tab and post the Hardware ID(s) listed.
Is it one of the following:
PCI\VEN_8086&DEV_A323Desc="Intel(R) SMBus - A323"
PCI\VEN_8086&DEV_9DA3Desc="Intel(R) SMBus - 9DA3"
PCI\VEN_8086&DEV_02A3Desc="Intel(R) SMBus - 02A3"
PCI\VEN_8086&DEV_19ACDesc="Intel(R) Atom(TM) processor C3000 product family Host SMBus - 19AC"
PCI\VEN_8086&DEV_19DFDesc="Intel(R) Atom(TM) processor C3000 product family Legacy SMBus - 19DF"
PCI\VEN_8086&DEV_34A3Desc="Intel(R) SMBus - 34A3"
PCI\VEN_8086&DEV_A2A3Desc="Intel(R) SMBUS - A2A3"
PCI\VEN_8086&DEV_A1A3Desc="Intel(R) C620 series chipset SMBus - A1A3"
PCI\VEN_8086&DEV_A223Desc="Intel(R) C620 series chipset - NS SMBus - A223"
PCI\VEN_8086&DEV_A123Desc="Intel(R) 100 Series/C230 Series Chipset Family SMBus - A123"
PCI\VEN_8086&DEV_9D23Desc="Mobile Intel(R) Processor Family I/O SMBUS - 9D23"