ethernet problem


I have mounted a mini-cluster system in my office, but i have some problems with it. The first one is that when the master computer get restarted i must to desconect the principal ethernet card, because if i don’t do this, the card get power off. I have installed windows and i have not the same problem, it seems like it is a kernel problem. The motherboard is MSI 790FX-GD70 AMD790FX AM3 FSB5200 4DDR3 PCIe.