Interface address sourced packets go thru default gateway on another interface

[Brian Hawk]

Hi ppl,

Sorry for the bizarre subject but I really didn't know how to put this on.

I have 3 interfaces: xl0, xl1 and rl0. rl0 is the where ppp daemon (for 
ADSL) runs on, so I also have tun0 which grabs the default gateway. My 
problem is with xl1 which is connected to a leased-line and has a static 
external IP, let's say A.B.C.D.

My problem is, packets generated with A.B.C.D source address does not go 
out thru xl1 but tun0 (which is the default gw). The problem also 
happens when an outsite packet destined for A.B.C.D arrives. The packet 
correctly arrives from xl1 interface but the response goes out from 
tun0. This is driving me crazy since it shouldn't really happen and it 
used not to happen. Everything was working fine until I don't know when 
and why, now I cannot send any packets out thru my xl1 interface by 
binding its source address to the packets.

Anyone has a clue why this might be happening?

-Brian