A try with OpenWRT 8.09 in April to setup a WDS with additional AP functionality and encryption, like described in the documentation, failed. So I keeped with my halfbroken solution running on DD-WRT, which is going a bit too commercial these days in my eyes.
Now I have found time to try OpenWRT again for this purpose, since the issue was fixed really fast. I just did setup a stock 8.09.1 installation and then dropped the following into /etc/config/wireless:
config 'wifi-device' 'wl0'
option 'type' 'broadcom'
option 'channel' '5'
option 'disabled' '0'
config wifi-iface
option device "wl0"
option network lan
option mode ap
option ssid "OpenWrt"
option encryption psk2
option key "keyforclients"
config wifi-iface
option device "wl0"
option network lan
option mode wds
option bssid 00:16:B6:19:63:C8
option ssid "OpenWrtWDS"
option encryption psk2
option key "pskforWDS"
And guess what? It worked like a charm! So I could replace the odd DD-WRT boxes. Anyways ... does anybody have an idea where to find the sourcecode of anything > v23 SP1?