Problem to route wireless on ubuntu 8.10

I just installed Ubuntu server 8.10, with a Ethernet PCI card and a wireless card (01:08.0 Network controller: RaLink RT2500 802.11g Cardbus/mini-PCI (rev 01)

LAN -----| LINUX BOX |----- WLAN
                     |
             INTERNET

The wlan is OK. This device ping others device on WLAN.
Route are Ok. Gateway, etc, etc, Ok.
ip_foward 1, and MASQUERADE on iptables.

But: a machine on LAN dont connect (ping, telnet, etc) a machine off WLAN.
LAN works on INTERNET, but WLAN dont work.

I just configured firewall like this a dozen times, but is first time in UBUNTU... Can The problem be relationed with the distribution. Linux firewall 2.6.27-9-server #1 SMP Thu Nov 20 22:53:41 UTC 2008 i686 GNU/Linux

The same device works with debian.

Some one can help-me?

IFCONFIG

eth0 Link encap:Ethernet HWaddr 00:04:61:7f:fe:7f
          inet addr:192.168.156.1 Bcast:192.168.156.255 Mask:255.255.255.0
          inet6 addr: fe80::204:61ff:fe7f:fe7f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:1992 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2068 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:214965 (214.9 KB) TX bytes:831175 (831.1 KB)
          Interrupt:21 Base address:0xe000

eth1 Link encap:Ethernet HWaddr 00:e0:7d:f8:12:df
          inet addr:189.35.160.231 Bcast:189.35.167.255 Mask:255.255.248.0
          inet6 addr: fe80::2e0:7dff:fef8:12df/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:1052 errors:0 dropped:0 overruns:0 frame:0
          TX packets:714 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:678672 (678.6 KB) TX bytes:115701 (115.7 KB)
          Interrupt:18

wlan2 Link encap:Ethernet HWaddr 00:0e:2e:57:ac:db
          inet addr:192.168.155.3 Bcast:192.168.155.15 Mask:255.255.255.240
          inet6 addr: fe80::20e:2eff:fe57:acdb/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:35 errors:0 dropped:0 overruns:0 frame:0
          TX packets:49 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3578 (3.5 KB) TX bytes:4692 (4.6 KB)

wmaster0 Link encap:UNSPEC HWaddr 00-0E-2E-57-AC-DB-63-64-00-00-00-00-00-00-00-00
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.155.0 0.0.0.0 255.255.255.240 U 0 0 0 wlan2
192.168.156.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
189.35.160.0 0.0.0.0 255.255.248.0 U 0 0 0 eth1
0.0.0.0 189.35.160.1 0.0.0.0 UG 0 0 0 eth1

oot@firewall:/etc# iptables -L -n -t nat
Chain PREROUTING (policy ACCEPT)
target prot opt source destination

Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
MASQUERADE all -- 0.0.0.0/0 0.0.0.0/0

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

root@firewall:/etc# cat /proc/sys/net/ipv4/ip_forward
1