After reinstalling 10.5.2 I have noticed that my internet has been lagging. I have cable internet and use a usb ethernet adapter. Any ideas on why it's lagging? I set my BIOS to default settings before installing 10.5.2 (thought something was wrong with my IDE settings) could that be the cause?

I had the same issue. What I did to solve this was to toggle 1394 (firewire) in the bios and reboot. This fixed forcedeth and enabled appleyukon.kext to detect my marvell yukon adapter.

toggle 1394 on or off?
i have the same problem but i think my firewire is off, actually..

@shitan, turn it off. Check your bios settings and see if it is on or off. The internet is still a little bit slow, but faster than before.

the thing is that 1394 has a security error anytime I boot up, this is why it is best to disable that through your BIOS settings. this should resolve that lag you are noticing.

@WinLinMac01 do you think anything else could also contribute to the lag? Because before, when I first installed Leopard and got a usb ethernet adapter, The internet worked just as well on Vista as on Leopard, but now even with 1394 disabled it is still a little bit sluggish.

May be I should read carefully the next time I respond, you said you have a USB ethernet adapter right? Thats probably the cause. I experienced a similar situation before a few years back with Windows XP. If I were you, try using a ethernet-to-ethernet connection. That should resolve the lag, I can guarantee you that. USB is the worst option out there, lol. really...

Well the only reason I am using usb on Leopard is because my two built in LAN lines on my nForce mobo don't work on Leopard and also my D-Link Ethernet card also doesn't work on Leopard, however it works on Tiger.

you have nforce lan? Oh, thats why. Try using a spare dedicated ethernet card. Thats what I am working with, and everything runs smoothly (no lag at all).

@Do you mean like my d-link ethernet card?