> 
> There are pure-AMD boards (the multiprocessor ones,
> because the VIA southbridge doesn't work in multiprocessor configurations),

Well, the south bridge is just a PCI device!  All a multiprocessor
platform does is give it cycles from two different masters, the same
could happen if any of the PCI cards in your system decided to access a
device on the south bridge (or ISA bus).

I guess it's just broken!  Mind you the PCI spec doesn't help.  In rev
2.1 (or maybe 2.2) they required devices to terminate read cycles with a
'cycle rerun' code (instead of stretching the PCI cycle) when forwarding
a cycle to a slow device.  Naive hardware expects the next cycle it sees
to be the rerun of the earlier cycle....

	David