Routing problems

[j.halifax .]

Hi All,

Could you please help me with routing in the LAN default GW box?

I have 
eth0 connected to Internet 
eth2 to internal LAN 10.255.250.0 
LAN default GW is 10.255.250.37
eth3 connected to other LAN

Route in the default GW (10.255.250.37):

Destination       Gateway           Genmask         Flags Metric Ref  Use Iface
192.168.180.0   *                       255.255.255.0   U      0      0        0  eth3
10.255.250.0     *                       255.255.255.0   U      0      0        0  eth2
link-local           *                       255.255.0.0      U     1003   0        0  eth0
link-local           *                       255.255.0.0      U     1004   0        0  eth2
link-local           *                       255.255.0.0      U     1005   0        0  eth3
172.17.0.0       192.168.180.100  255.255.0.0      UG    0      0        0  eth3
default             dsl-router            0.0.0.0             UG    0      0        0  eth0

>From the LAN default GW (10.255.250.37) 
- I can ping 172.17.1.50:
  PING 172.17.1.50 (172.17.1.50) 56(84) bytes of data.
  64 bytes from 172.17.1.50: icmp_seq=1 ttl=253 time=5.62 ms
  64 bytes from 172.17.1.50: icmp_seq=2 ttl=253 time=3.29 ms

>From other boxes in the same LAN (e.g. 10.255.250.38)
- I cann't ping 172.17.1.50
- I cann't traceroute 172.17.1.50: It goes to LAN default GW 
  10.255.250.37 and then to its default GW dsl-router on eth0
  instead of eth3 (so that the routing rule for 172.17.0.0 doesn't 
  match for 172.17.1.50)

Can anybody help pleasee?
Thank you so much!
jh