DNAT sends packed by wrong interface

Hi,
I have encountered a problem when using DNAT:

Scenario:

iptables v1.2.7a
Linux 2.4.20

Computer A:
eth0 ip 150.128.49.236/21
eth1 ip 10.1.1.1/24
iptables -t nat -A PREROUTING -d 150.128.49.236 -p tcp --dport 8080
-j DNAT --to-destination 10.1.1.2:80

Computer B:
eth0 connected to eth1 of computer A, ip 10.1.1.2

Client C:
ip 213.171.249.250
When accessing port 8080 of A is redirected to port 80 on B, OK

Client D:
ip 150.128.49.219, in the SAME NETWORK of A (eth0)
When connecting to A, port 8080, the configured DNAT redirects the
packets to 10.1.1.2:80 , BUT PACKETS ARE SENT to interface ETH0, not to interface eth1 as expected, so , do not arrive to B.
The same problem occurs for any client in the network of A

Some idea?

Thanks

Sorry, I have solved my problem

I have:

ip rul add from 150.128.48.0/21 table 1

and

ip rou add default via 150.128.48.1 table 1

The rule is applied, and as router 150.128.48.1 is in eth0, kernel decides to send pakets via eth0 ????????