One setting that works:

* Put both on the same channel
* Assign both the same essid
* Turn off frame bursting on both sides
* Turn off 802.11g protection on both sides
* Enter the belkins mac address into the wds settings on the airstation
* Select 'auto' for the wireless bridge settings on the belkin


Tada.

Now, googling gets really interesting:
[http://skaya.enix.org/wiki/Broadcom96345] explains some things how to
use the Linux(!) on the router

Most important detail there:

rdb@lgb:~$ telnet 192.168.1.1
Trying 192.168.1.1...
Connected to 192.168.1.1.
Escape character is '^]'.
USR ADSL Gateway
Login: admin
Password:
> sh

Rest is left as an exercise to the reader....