I finally got 10.5.2 working on my AMD64 3200+, DFI Lanparty nf4 Ultra-d. However, this morning both nforce4 lan and marvell yukon stopped working. I keep getting a self-assigned ip (169...) no matter what I do. They both work fine in windows. Help me!!

I forgot to mention, I'm connected directly to the cablemodem, no router.

Use manually options

I'll try that, but ocassionally my ip changes and I would have to switch to windows to copy that, right? Isn't it possible to use DHCP?

I can use auto DHCP with only 1 kext that I have found. I will attach it for you to try.

Thanks eddie! It didn't work though, I'm still getting the self-assigned IP. Manual setup didn't work either.
One thing I noticed, while using nForce4 Lan, System Preferences shows Marvell connected (which isn't true).

Any ideas?

I am not sure where you see Marvell connected at in system preferences. I looked around in mine and saw no mention of it. All i can suggest is maybe try different forcedeth.kexts. You may find one that works better for you. Oh and not that it probably matters, do you have boot rom enabled on your nforce LAN? Mine is turned on and my LAN never freezes with auto DHCP.

Well, I enabled Boot Rom and still nothing. The weird thing is that none of them work, and both give me the same ip.
In System Preferences > Network, Marvell Yukon used to appear as connected. It doesn't do that anymore, though.
Any other ideas?

Make sure your deleting the old one prior to putting the new one in /system/library/extensions

Yes eddie, I did that, repaired permissions... but no change :(

Well i guess you may be stuck with manually setting it, or if you have the 2nd ethernet try using it instead.