KDE>SYSTEM>Configure your computer>Network and Internet>monitor connections.
what does it say?? (connected or disconnected)
mine was always disconnected at boot dispite being started on Mandrake 10.1 install when reinstalling fresh.
Have you checked the /etc/rc.d/rc5.d directory for the sysinit startup script labelled "S10network"? That should be a symlink to /etc/rc.d/init.d/network
link /etc/rc.d/init.d/network /etc/rc.d/rc5.d/S10network