If have the following set for some port forwarding that I need done, which works well...

/sbin/iptables -t nat -A PREROUTING -p tcp -i eth0 -d 196.11.11.11 --dport 80 -j DNAT --to 10.0.0.2:80
/sbin/iptables -t nat -A PREROUTING -p tcp -i eth0 -d 196.11.11.11 --dport 389 -j DNAT --to 10.0.0.2:389

then once I set the following for SNAT so my local machines can get internet access my port forwarding 
stops working.

/sbin/iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 196.11.11.11


Is there something im not doing right? can someone point me in the right direction.

tx.