So, for now, the nslu2 is accessible only via samba and I had to mount my shares via samba rather than nfs. Installed smbfs
sudo aptitude install smbfs
smbclient -L
mount -t smbfs -o username=
<
>
It got mounted and I could browse the NAS. Now to make it permanent, I found an excellent resource (http://www.mattvanstone.com/2006/06/automatically_mounting_smb_sha.html thanks to Matt). Not that I didnt know this before, but I was lazy on a saturday morning and wanted to avoid reading man pages :-)
sudo vi /etc/fstab
sudo chmod 600 /home/<user>
sudo mount -a worked.