I use a pre-release version of RC5 (svn build 8406, released in a topic by Eko) that has been working very well for me on my WHR-G125.
By the way you described it, I seem to have used the same procedure as you. Unless you followed a different wiki than I.
Basically I just enter these commands in startup script. Administrations > Commands
ip neigh change 192.168.1.12 lladdr XX:XX:XX:XX:XX:XX nud permanent dev br0
ip neigh add 192.168.1.12 lladdr XX:XX:XX:XX:XX:XX nud permanent dev br0
Replace XX with your PC's MAC address.
I suppose the above was for a static ARP entry. But I also set a static DHCP entry just in case. And forwarded port 7 udp as well.
I was able to wake up my PC in the LAN from another PC by using that website I posted earlier. The website is on the internet, so effectively this was wake on WAN because the magic packet was being sent from the computer on the internet.