Marvell Yukon PCIe Gigabit Card

At my work we have several machines that have these types of network cards installed. Since this time we have been noticing several weird things.

First, for gigabit cards, they seem to run very slow when doing network copying and accessing server drives.

we also have this problem where computers reboot themselves after they have been shutdown. The user will shutdown the computer and it will be completely off. After a random amount of time the computer will come back on by itself. Sometimes after like 15 minutes, sometimes by the next morning.

Anyone have any problems with these cards or know anything about them?

Oh yeah, they are integrated into the new Intel socket 775 boards.

My PC:
Abit AX8 Socket 939 VIA K8T890
AMD Athlon 64 3200 Winchester
Sapphire Radeon X700 Pro 256 Mb PCIe
WD Raptor 37 Gb SATA
Corsair 2x512 PC3200 DDR Dual-Channel Platnium Edition

Wake on LAN feature in bios might be enabled which could cause weird problems if you do some for of network imaging or something to that effect.

You might want to set the cards to 100/full, that is if you have 10/100 switches and 10/100 nics in your servers. To get the full potential of gigabit, you'll need cat5e (not just cat5) plus gigabit capabable switches and gigabit nics in the server.

Might be the network card or maybe a problem with a managed switch?
Have you tried to put in a PCI NIC to see if that fixes it yet?