Virtual Box guest OS Solaris 10 U9 networking

I'm running Virtual Box 4 on Ubuntu 10.04 in my Toshiba laptop. I downloaded Oracle Solaris 10 9/10 Virtual Machine for Oracle VM VirtualBox and the installation was pretty simple and straight forward. My VBox was configured to use NAT. I chose networked - yes and name service - none during installation. After successful installation I took the following steps to enable networking by configuring DNS.

1. Added "nameserver 192.168.1.1" at /etc/resolv.conf
2. Aadded "10.0.2.2" at /etc/defaultrouter
I took these two information from another virtual machine, Solaris 11 Express 2010.11
3. Copied /etc/nsswitch.dns to /etc/nsswitch.conf
4. Enabled dns/client service using SVCS (svcadm enable dns/client)

However, I was not able to access internet after taking these steps. "netstat -rn" output was showing the default gateway was not configured properly and "route add" command was failing as well. My system was not able to ping the gateway. I got fed up with this and ran "sys-unconfig". After that I took the following configuration steps  -

Networked -> Yes
DHCP -> yes
IPV6 -> No
Kerberos -> No
Name Service -> None
NFSV4 domain config -> derived by system

and repeated steps 1-4 again. After a reboot networking started working as intended.