Phoneline network card keeps going bad??

Hi,

I purchased the m7vib and have installed and replaced the linksys HPN200 - HomeLink Phoneline 10M Network Card in it 3 times. The card works for about a couple of weeks and then goes bad. Called linksys and they think that the motherboard might be the problem. The card fits in a PCI slot. Have put other kinds of nic cards in the slot and they work fine. If anybody has an idea as to what my be wrong please let me know