name resolving error

[G Rajesh]

Hello,
I have two systems running on Ubuntu 5.10 - one P4 and another amd64. I
decided to connect them. 

1. I edited /etc/fstab by adding: 
//192.168.1.20:/home /net nfs rw 0 0 in the client system and 
2. edited /etc/exports of the server as:
/home 192.168.1.10(rw,async)
3. Earlier I have assigned static ip addresses for the eth card through
sytem>administration>networking as 
192.168.1.20 for server
192.168.1.10 for client
4. I have added these ipaddresses along with host & domain names
in /etc/hosts.
192.168.1.10 primary primary.grajesh.in
192.168.1.20 secondary secondary.grajesh.in

But, while booting (or when trying to mount nfs later), I get a message
as:
"mount: can't get address for //192.168.1.20"
Where do I go wrong? Please help. Thanks in advance.
Regards,
Rajesh