Two bridged NICs don't work with same driver.

I don't know where to send issues with this kind of bug.
If you know right bug-tracker for Virtio paravirtualized drivers for Windows guests tell me please.

I have two bridged NICs in a Windows guest Server 2008R2.
RedHat released new windows guest drivers in the summer 2012 and still these drivers don't work when them installed for both NICs.
If I install same driver for both NICs (last one made at 22.01.2013, version is 61.64.104.5200) then one NIC works fine, but last one can't find DHCP server at all.
When I downgrade driver for any one NIC to version 61.63.103.3000 (from 03.07.2012) then both NICs start working well, and I can see dhcp requests from these NICs in dhcp-server's logs.

Latest Proxmox VE 2.3 is installed:
pveversion -v
pve-manager: 2.3-13 (pve-manager/2.3/7946f1f1)
running kernel: 2.6.32-18-pve
proxmox-ve-2.6.32: 2.3-88
pve-kernel-2.6.32-10-pve: 2.6.32-63
pve-kernel-2.6.32-18-pve: 2.6.32-88
lvm2: 2.02.95-1pve2
clvm: 2.02.95-1pve2
corosync-pve: 1.4.4-4
openais-pve: 1.1.4-2
libqb: 0.10.1-2
redhat-cluster-pve: 3.1.93-2
resource-agents-pve: 3.9.2-3
fence-agents-pve: 3.1.9-1
pve-cluster: 1.0-36
qemu-server: 2.3-18
pve-firmware: 1.0-21
libpve-common-perl: 1.0-48
libpve-access-control: 1.0-26
libpve-storage-perl: 2.3-6
vncterm: 1.0-3
vzctl: 4.0-1pve2
vzprocps: 2.0.11-2
vzquota: 3.1-1
pve-qemu-kvm: 1.4-8
ksm-control-daemon: 1.1-1