The key thing is in your routeadm output. By default in Solaris 10 IP forwarding and routing are off.
To enable IPv4 forwarding, as you have, you can set
#routeadm -e ipv4-forwarding
To enable routing, use
#routeadm -e ipv4-routing
To make your changes take effect and start the routing daemon, use
Use the same commands (with ipv6) to enable the IPv6 routing and forwarding.
These changes persist across a reboot.
This should take care of your problem.