What network settings are lost?
Try running the anti-parasite suite offered here:
I set up a wireless router a few months ago, networking my sony vaio desktop (wired) to my apple powerbook (wireless), and sharing a DSL connection. The problem is that the vaio doesn't remember any of the network settings after shutdown/restart, so I have to go to the "set up a network" wizard every time the machine is rebooted to get back online (there are a few users on the vaio, and they tend to turn the machine off instead into standby, despite what I advise). If I logout, or put the machine into standby mode, it remembers the settings just fine.