I've lost my WAN connection!

[macstatic]

For some reason I've lost my Internet connection via ethernet on my Powerbook G4.
I'm getting a local IP address from the router, but there's no connection to the Internet. Airport on the other hand works fine.
I also have an iMac which is connected to the same router. It works fine, so I tried it's ethernet cable with my Powerbook. Still no go -so the cable isn't at fault.

Next I tried connecting my Powerbook directly to my cable modem, bypassing the router. Nope, still doesn't work -so it's not the router at fault.
This must mean the problem is with my Powerbook, but I have no idea where, how and why.
I've already tried running Applejack and various jobs with Onyx, but that didn't change anything.

The computer's a 1.67GHz Powerbook G4 running MacOS 10.4.11.

 

[macstatic]

I don't know what caused it, but it seems that things are back to normal now
Having previously installed Applejack for this sort of thing, but not relieving the issues after running it I ran it once more only this time I entered applejack AUTO (in capital letters for a deep and more thorough examination/fix). Looks like that did the trick! I'm still wondering what happened though and why.
Shocking