Richard,
Thanx for posting to our forum. I encountered the same issue you are explaining when I wrote the FPP papers. I made a mental note to go figure out what the issue was, however I changed jobs before I ever root caused it.
I suspect it has to do with the actual network stack running on your server where the VF's are instantiated. I think the stack gets a bit confused because all the VF's are on the same subnet.
My solution for this was to put each VF on it's own subnet, or to put it on its own VLAN. I bet if you try that, you will get the results you are looking for.
In the meantime I will go pester my co-worker who owns the SR-IOV technology and ask him to go do some digging.
thanx,
Patrick