That shouldn't happen. There is something wrong with the server config. Our guys used clones and put the same MAC on each server. That is just wrong and when they realised that the fault was theirs (server guys never have to prove anything, it's always our job to show them the network is right). You have to change the MAC on each server if you cloned them.
Not sure if this is exactly your problem, but I doubt it's a switch problem. The switches only learn the MACs from the servers after all. If the servers are wrong....
Regards,
Ian
