Trust me when I say that i've spent tons and tons of hours trying to get the Wireless 360 controller to work.
The Xbox 360 controller is in a different format than what the old FFXI config is used to, so it can't read the triggers.

If you messed with XBCD you could get this to work. However, there is no method to get this to work with the Wireless controller only the wired.

I just pretty much use a PS3 controller now.