A Newbie Response--proceed with caution
Hopefully you get another more experienced response because I don't really understand this, but for what its worth, I had this too just this past week and got help with my applecare/calling support.
Running 10.4.11 on pb15, the support guy had me log into a second account and try opening system preferences, and network, and with that the slip message that you/I got did not show up.
From that he had me go mac hd>library>preferences>SystemComfiguration then drag the last folder to the desktop, then reboot. My understanding is that upon rebooting, systemconfiguration preferences is then regenerated from scratch, which solved the problem, and I could/did trash the old folder. Now all is good.
Maybe someone can explain the whats and whys.
Hope this helps, or leads to further research. Good luck.