Footer not centering

My blog is at:
http://blog.phantasypsalteries.com

I’m not sure if it’s a compatibility issue, but I’ve noticed some hiccups with the layout of my blog. First of all, the footer background image is not centered in the middle of the page, so it appears disconnected from the rest of the blog. But it’s not only off center, but it looks like its missing a gap too – my background color is blue, but the footer should have a white b/g to match the “notepad” style layout of the blog.

A second problem I’ve noticed, is that in Firefox, the b/g image for the main content area isn’t loading, and it just shows up as my default light blue background color with text on top. The b/g image appears to load fine in IE.

Can anybody give me any pointers? I’ve tried fumbling around with this thing, but I really don’t know all this .php and .css stuff very well.

Thanks,
Eric