We are using a linksys wap54g and we were facing a lot of difficulties configuring it. First of all it does not have a web interface. The easiest way to connect and configure is:
Make sure your computer ip is 192.168.1.100
The device ip is for me : 192.168.1.245
Try to ping to the device : ping 192.168.1.245
If it does not ping or you get an error while using the setup from the cd do the following:
Press the small hole in the back reset button with a pen tip and hold it for 1 minute
Disconnect the power cable and put it back
Try again the setup or the ping.
It worked for me it will work for you.
Use Dynamic IP if you are using the AP for internet and you dont know the Gateway IP.
Try with No Security first. Then provide the security and check. Best of luck.