Weird problem building original Asus 1.2.3.9 firmware

Hi all.

I'm trying to customize the original WL-HDD firmware (it actually suits my purpose better than Oleg's firmware, since I only need bridging, samba and DHCP server without other stuff).

I built everything ok (after some problems), did customizations I wanted and everything looks peachy... except that I cannot change the default IP address of the router. I changed other defaults in /src/router/mipsel/shared/defaults.c (or defaults_HMD.c if you're building WL-HMD), and everything looks fine. I changed the LAN_ipaddr setting in this file, but it remains fixed on 192.168.1.220 when I finally build the firmware. All other settings (wep key, dhcp pool, changes to the router web page etc.) that I specify get changed the way I want them too, but for some reason this change doesn't make it to the final firmware.

Is there a way to set this using a post-boot script? (like the post-boot script in oleg's firmware). I was considering making a script and packing it into the firmware, but I don't know how to name it and where to put it so it would get executed...

I got totally stuck. Any ideas (Oleg? Antiloop? Anyone?) would be really really appreciated. Thanks in advance!