the best driver is the ipw2200. For WPA support you need ARC4 cipher algorithm Michael MIC and AES compiled into the kernel or as modules. You also should be running the latest version which is 1.0.4. initial support was put in i believe at ver 1.0.2.
It also would help greatly is you gave more information than its not working. Please provide at least the distro you are running so someone can help you directly or point you in the right direction.
the default naming of your network interface depends on the driver. ipw2200,prism54 is "ethx" and madwifi is "athx" for example.