The brief answer is "sort of". I could not get the setup utility to work, and box for the range expander claimed that it was compatible with with wap54g, wrt54g and wrt54gs (which if I'd known, I wouldn't have bought the wre54g. Still with me? enough model numbers?
Unplug the network cable from the AP. Don't use the queasy set up, it doesn't seem to work.
What you have to do is to make sure that you have the latest firmware on your router. Then turn off WEP/WPA on your wireless router, then when you press the easy setup button on the wre54gs, it should be able to connect. Remember what your router security settings were.
Now go to address 192.168.1.240 (which is the AP), password is admin. Type in your security settings and save them. You will lose contact with the AP.
Re-enable your security settings on your router and turn your AP off and on. After a nail biting few seconds, both lights should go blue, meaning that it has a connection.
Yo can check the connection on the wireless status tab of your router status management page (192.168.1.1), and should the address and MAC for the AP.
If you need to changethe config os your AP, then you are probably best off resetting it and removing security from the router temporarily to alter both configurations (AP and router), for example to change the SID.
I hope this is useful to someone out there. This is a couple of hours of my life that I won't get back (thanks to Linksys).
