Hmm I'm just getting the 'an error occurred, power off your system' message with this footer file. Did this footer file work for you?
Also a cool site I found for save types:
http://offlinelistgba.free.fr/index.php
As another user already mentioned, Advance Wars is indeed flash
edit: I got Advance Wars to save pokemoner! If your footer file works for you then awesome, maybe I just installed it incorrectly or something. But if you can't get it to save let me know and I'll send you my settings for the footer file