iptables SNAT failing to work on second gateway.

[Louis]

Hello,

i have two gateways.
gateway 1 == eth1
gateway 2 == ppp0
lan == eth0

eth1 is the deafault gateway(i do not want to change the deafault gateway)

SNAT works fine if i use eth1 and it's ip.

It fails when i try to use ppp0 and it's ip.

here is a screenshot that shows what is not working

http://img82.imageshack.us/img82/1038/91629062qv2.jpg

how ever i kinda get it working when i do this(trying to force it's hand)

iptables -A PREROUTING -t mangle -i eth0 -s 192.168.1.102 -j MARK 
--set-mark 1
iptables -t nat -A POSTROUTING -s 192.168.1.102 -o ppp0 -j SNAT 
--to-source 60.241.215.xxx
ip rule add fwmark 1 table TPG

IPTRAF output:
ICMP echo req (60 bytes) from 192.168.1.102 to 206.190.60.37 on eth0
ICMP echo req (60 bytes) from 60.241.215.xxx to 206.190.60.37 on ppp0
ICMP echo rply (60 bytes) from 206.190.60.37 to 60.241.215.xxx on ppp0

so it gets close in that case but it will not forward the reply to 
192.168.1.102

other info that might be of use:
root at 1:~# uname -r
2.6.27-9-server
i've patched kernel with http://www.ssi.bg/~ja/patch-2.6.27-ja1.diff 
made no difference.
same result when useing MASQUERADE

i hope this is enough infromation

Thanks.