[c-nsp] Quad Sup6t 6807, ARP issue.

[Hefin James [ahj]]

Not getting much luck via our support provider on this one.
We are seeing ARP packets being dropped within the VSS for some ARP packets. (We still have single connected sites to the VSS, hence the need for Quad Sup6T's)
Some ARP requests are arriving on one chassis within the VSS, and are not being broadcast on the other chassis, resulting in the obvious communication loss.
Manually adding the ARP entry statically to the problem system, and communication is restored.

We are currently running IOS 15.4(1)SY2, which is fairly recent, and the 4 VSS links are connected on the Sup6T's with each Sup6T connecting to both Sup6T's on the other Chassis. There is a bug reported as CSCve73632 which doesn't list our current IOS version as being affected, but we've already upgraded from 15.3(1)SY1 due to this issue. I don't want to upgrade again, only to find that the issue is still there.

Anybody else on this list see this or have had experience of it?

Thanks,
Hefin