Has it got two ethernet ports or just the one? I have an nforce4 chipset with the nforce ethernet and a marvell gigabit ethernet and the marvell has crappy linux drivers, works for some not for others. I just use the nvidia one and it works great, that links specifically lists a marvell ethernet adapter, so is the marvell the only one or..?
You can get updated drivers off the manufacturers site for the marvell adapter, might be worth a shot.
http://www.marvell.com/drivers/search.do