2008R2 realy slow network

[Gianluca Nanoia]

Hello I have 5 Bl465g5 with Microsoft Windows 2008 R2 with HyperV role installed.
The servers are plugged through an HP Virtual connect to a Procurve switch
If I try to send a file from a pc (on the same procurve switch) to one of these servers the maximum speed I can reach is 30kb/s.
I have latest firmware and drivers, and I tried to disable offload checksum on the server. Sniffing through Wireshark I get many "TCP segment of a reassembled PDU" and "TCP REtrasmission" or "TCP-Out-OF-Order" messages.
Hope someone can help me
Thank you in advance

[WFHC-WI]

You may wish to try enabling flow control on your NICs and switch ports.

[Gianluca Nanoia]

1 month later, with new drivers and firmware, same problem.

The problem was solved turning off and then turning on the switch :S