Centos – openswan multiple subnets routing issue

I am trying to setup an OpenSwan(2.6.32) on CentOS 6.5 (final) to connect the remote VPC gateway on Amazon cloud. I got the tunnel up. However, only the traffic from/to the last ip range defined in leftsubnets is routed. The first one works for a brief second (maybe before the second tunnel was up), then no more routing. Below is my configuration.

conn aws-vpc
    leftsubnets={10.43.4.0/24 10.43.6.0/24}
    rightsubnet=10.43.7.0/24
    auto=start
    left=206.191.2.xxx
    right=72.21.209.xxx
    rightid=72.21.209.xxx
    leftid=206.191.2.xxx
    leftsourceip=10.43.6.128
    authby=secret
    ike=aes128-sha1;modp1024
    phase2=esp
    phase2alg=aes128-sha1;modp1024
    aggrmode=no
    ikelifetime=8h
    salifetime=1h
    dpddelay=10
    dpdtimeout=40
    dpdaction=restart
    type=tunnel
    forceencaps=yes

After start IPsec service:

# service ipsec status
IPsec running  - pluto pid: 8601
pluto pid 8601
2 tunnels up
some eroutes exist

# ip xfrm policy
src 10.43.6.0/24 dst 10.43.7.0/24 
dir out priority 2344 ptype main 
tmpl src 206.191.2.xxx dst 72.21.209.xxx
    proto esp reqid 16389 mode tunnel
src 10.43.7.0/24 dst 10.43.6.0/24 
dir fwd priority 2344 ptype main 
tmpl src 72.21.209.xxx dst 206.191.2.xxx
    proto esp reqid 16389 mode tunnel
src 10.43.7.0/24 dst 10.43.6.0/24 
dir in priority 2344 ptype main 
tmpl src 72.21.209.xxx dst 206.191.2.xxx
    proto esp reqid 16389 mode tunnel
src 10.43.4.0/24 dst 10.43.7.0/24 
dir out priority 2344 ptype main 
tmpl src 206.191.2.xxx dst 72.21.209.xxx
    proto esp reqid 16385 mode tunnel
src 10.43.7.0/24 dst 10.43.4.0/24 
dir fwd priority 2344 ptype main 
tmpl src 72.21.209.xxx dst 206.191.2.xxx
    proto esp reqid 16385 mode tunnel
src 10.43.7.0/24 dst 10.43.4.0/24 
dir in priority 2344 ptype main 
tmpl src 72.21.209.xxx dst 206.191.2.xxx
    proto esp reqid 16385 mode tunnel

I don't think firewall plays any role here, as I turned it off entirely just to test out the connections. routes are working as expected too. If I define single network on the left side, individually on a separated test connection, I can reach either subnets. Only when I define leftsubets, then, whichever range comes last will get routed in the end. Whichever comes first, works for a brief second before it stopped routing.

I could not find anyone on the internet have the similar problem… can someone please enlighten me?

cheers,

bo