I configured my ethernet card using the system setting | network GUI interface, but when I try to activate it, the window saying that that activation is taking place opens, there is a pause, and the window closes without any error message, but the card is still set inactive and cannot ping/be pinged.

If, however, I use "ifconfig eth0 nnn.nnn.nnn.nnn", with the same address as given in the GUI window, the card comes to life and can ping/be pinged quite happily.

When I next boot the system, although the loader says that eth0 has been started [OK], the card is inactive until I issue the ifconfig command.