I just had the same problem with my 04 that I just bought (used). I got to ride it for a week before it wouldn't start on it's own. I got an exact match, factory replacement battery from motorcyclebatteriesusa.com for nearly $60 less than the STealership wanted (almost HALF!). The only problem I had with buying from them was the unusually long "Free" shipping time. Purchased on 10/27, received 11/07. Willing to wait, it is the way to go!
Use coupon code "MBUSA545"... this code may be on the batteries page:
http://www.motorcyclebatteriesusa.com/battery-details.asp?battery=750
My cost was $85.12... STealership here cost $135 (and that was the best they could do - I asked!!)
Oh, if you bought the bike new from the STealership, and you still were in good with the them after the purchase, they may give you another one "Under Warranty," but it will probably be an acid filled "look-a-like"... Less cost to them and gets you on the road... Becareful!!
Good Luck!!