I have two machines with the same problem. Both running 9.3. At startup the network will not establish a wired network connection. I can get both running using /etc/init.d/network stop start (restart does not work) or by running through yast-->network devices-->network card and running through default steps.

Both machines start network services at boot but do not find an IP. Network is enabled in the run level editor.

Machine one: desktop with an onboard Realtek LAN card.
Machine two: laptop with an Acer onboard LAN card.

The desktop had 9.2 before with out any network trouble at all. Clean install for 9.3.

I have a similar problem with wifi cards in SuSE 9.3. If I open up the network configuration windows in Yast, the wifi card stops working until I completely reboot. A network restart from the command line doesn't fix it. I think SuSE 9.3 might have some weird bug in it.

It turns out the laptop has a Realtek card also. RTL-8139/8139C/8139C+ (rev 10)
I went to the Realtek site but they don't list drivers for the 2.6 kernel. The Google search continues.