Airport Express: Can't connect to existing network in Client/Bridge Mode

I have a new Airport Express that I'm trying to use to connecto to an existing wireless network to provide wireless access to a Mac Mini with a broken antena.

The Mini has it's non-functioning wireless turned off, an ethernet cable connected to the WAN port of the Airport Express and I'm trying to follow the directionf from here: http://support.apple.com/kb/HT1731?viewlocale=en_US&locale=en_US The relavent portion is:

Using AirPort Utility 6

1. Connect an appropriate cable between the AirPort Express and the device it will serve.
2. Plug the AirPort Express into a power outlet.
3. After the AirPort Express starts up, select it in the AirPort Utility screen.
4. If you are now repurposing the AirPort Express, first reset it from Base Station in the menu bar and selectRestore Default Settings.
5. After the AirPort Express completes the restore process, choose it from the Wi-Fi menu in the upper-left corner.
6. Click the Other Options button.
7. Select "Add to an existing network".
8. CHoose the Wi-Fi network name from the Wireless Network Name menu that you wish to join and click next.
9. Enter the password to this network if required.

I cannot get past step 3 w/o actually configuring the AE. If I follow the propmts on the screen (by jumping to step 7), I get the error "No Base Stations Found." I know the wireless router works because the Mini can reach it even with it's broken antena, and three other decives in the samre vicinity can connect to the existing wireless network.

If I turn on the wireless on the Mini, the Airport utility find the newtork, but gives a "unknown error" when trying to connect. If I try to use the ethernet port on teh AE instead of the WAN port, the Airport Utility says that the ethernet cable needs to be connected to the WAN port, but Airport Utility shows a diagram for connecting to the Cable Modem Directly.

I'm pretty stumped here.

Ray