aligning background picture & blog

[Maz]

http://arashmazinani.com

I currently have my background picture on my blog the actual picture size is 1612x1700

I have the follow coded in my style sheet;

background: url(images/background.jpg);
background-repeat:no-repeat;
width: 1612px;
height:1700px;
color: #000000;
font-size: 12px;
font-family: Helvetica, Optima, Arial;
margin: 0px auto 0px;
padding: 0px;

Now, I have a couple of issues, even though the image size is in the code, at the bottom of the blog there is a thick white band running across the bottom horizontally. How can I get rid of that.

Also, the blog itself is aligned in the middle, and slightly up rather than smack bang in the centre, how do I get the blog to sit in the centre so there is an equal amount of the background picture showing above and below the blog itself.

Thank you in advance