I experienced the same problem, not mounting nfs shares at boot time on hardy (diskless client).
I solved the problem adding "auto eth0" to /etc/network/interfaces. Actually eth0 is already configured by the kernel when booting from the net, but the interface is not brought up "officially" when the keyword auto is missing in /etc/network/interfaces, according to /etc/udev/rules.d/85-ifupdown.rules.
I experienced the same problem, not mounting nfs shares at boot time on hardy (diskless client). interfaces. Actually eth0 is already configured by the kernel when booting from the net, but the interface is not brought up "officially" when the keyword auto is missing in /etc/network/ interfaces, according to /etc/udev/ rules.d/ 85-ifupdown. rules.
I solved the problem adding "auto eth0" to /etc/network/