I also get this problem. However, it doesn't even work when setting to "noauto" in /etc/fstab and then try to mount it from /etc/rc.local, I get this error message:
mount.nfs: DNS resolution failed for myserver: Name or service not known
But it does work to mount it from /etc/gdm/PostLogin/Default.
I use DHCP. I suspect that NFS mounting does not wait for the DHCP lookup to finish as it should.
I also get this problem. However, it doesn't even work when setting to "noauto" in /etc/fstab and then try to mount it from /etc/rc.local, I get this error message:
mount.nfs: DNS resolution failed for myserver: Name or service not known
But it does work to mount it from /etc/gdm/ PostLogin/ Default.
I use DHCP. I suspect that NFS mounting does not wait for the DHCP lookup to finish as it should.