Hmmm. Have you restarted/rebooted Zeroshell after applying the patch?
The reason I ask is the magic that gets incoming connections to have packets returned to the same gateway is in the NB_CT_PRE chain which the patch adds. However I don’t see that chain at all in your iptables listing.
There should be an entry that looks something like this:
Chain NB_CT_PRE (1 references)
pkts bytes target prot opt in out source destination
25951 1319K MARK all -- ppp0 * 0.0.0.0/0 0.0.0.0/0 MARK set 0x66
45921 2993K MARK all -- ETH01 * 0.0.0.0/0 75.144.252.181 MARK set 0x65
And the PREROUTING chain should look something like this:
Chain PREROUTING (policy ACCEPT 30M packets, 18G bytes)
pkts bytes target prot opt in out source destination
16M 9594M CONNMARK all -- * * 0.0.0.0/0 0.0.0.0/0 CONNMARK restore
517K 38M NB_CT_PRE all -- * * 0.0.0.0/0 0.0.0.0/0 state NEW
517K 38M NetBalancer all -- * * 0.0.0.0/0 0.0.0.0/0 state NEW
Your PREROUTING chain does not have the reference to NB_CT_PRE nor does NB_CT_PRE exist.