Hi again,
I currently do not have a switch available that I can use to reproduce the same layout as you have. I'll see about getting one. In the meantime, I found something interesting on Cisco's website about interoperability with Intel LAN solutions at http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a00800a7af0.shtml#nic_comp
Here is their recommendation to workaround connection issues:
1. In Device Manager, choose Network Adapters and then the Intel LAN adapter you have.
2. At the Power Management tab, uncheck Allow the computer to turn off this device.
Please give this a try and let me know what happens.
Our engineering team would definitely need to have a system exhibiting this behavior in order to debug and find a solution. If we are unable to find the right combination here to reproduce the problem, would it be at all possible for you to send us the failing system?
Lois