basically, even on the new 8601, you can autodetect all you want but some settings seem to not work. Very frustrating. I'll have to look and see what hooks are in there, I no longer remember.
Since I'm in that code currently copying and looking for my 440bx port. I noticed that the IO_BASE for the smbus in x_early_smbus_init.c is set to 5000. This will suffer the same problems that my 440bx V1 had where this io base will conflict with a device in the PCI IO allocations.
I would suggest you move that to an address < 1000.