Failed Intel Pro/1000PT Dual Port

Hi all,

I've been using two of Intel Pro 1000 dual port for the last 4 months, but both of them failed on me after a month.
I bought them from Amazon, and I though the first one is defective, but apprantely this second NIC also failed too.
The NIC adapter has two ports, and I'm using one of the ports along with my integrated motherboard NIC as bonding.

I'm using them without a switch with balance-RR, balance-tlb.
Each NIC is using a different PCI-E slot after the first one dead.
OMV is shutdown/wake up on daily basis by cron job.
It also using a UPS: Cyber Power System, Inc. CP1500 AVR UPS

Update: My third NIC is now dead after two months.
Regardless whether I connect my ethernet via the router or through the UPS, it's still died.

I can't find out the culprit.

http://www.amazon.com/gp/produ…oh_aui_detailpage_o01_s00

Linux server 3.16.0-0.bpo.4-amd64

description: Desktop Computer
    product: All Series (All)
    vendor: ASUS
    version: System Version
    serial: System Serial Number
    width: 64 bits
    capabilities: smbios-2.8 dmi-2.7 vsyscall32


 description: Motherboard
       product: Z97-A-USB31
       vendor: ASUSTeK COMPUTER INC.
       physical id: 0
       version: Rev 1.xx


 *-firmware
          description: BIOS
          vendor: American Megatrends Inc.
          physical id: 0
          version: 2801
          date: 11/11/2015
          size: 64KiB
          capacity: 8128KiB