Yeahh... here's my story with that exact mixer.
bought it, was not able to get the firewire to work. Call them.. spent a few hours.. no resolution. Changed my firewire card in computer. Changed the firewire cable. Still not working. Called the vendor i purchased from.. could not fix it. Call Alesis.. spent many hours.. could not fix it... BUT agreed they would take a look (under warranty). Paid to ship to them.. they finally agreed it was busted and send a 'new' replacement.
Replacement arrived, the firewire is detected, but does not work properly, tracks are peaking/distorting/overall messed up.
Money spent card (75$), cable (30$), shipping to repair (~100$).. time spent .. probably 15 hours or so.
So.. not that great a deal. I still use it, but just use the main out or 2 track out.
If it's the firewire feature you want.. i'd recommend something else. If it's not the firewire you need, save your money and buy the USB version of this alesis mixer.