Div Element Won't Center

I’m trying to center a div element and I can’t seem to figure out why it isn’t centering. I know there is something conflicting, but I can’t seem to figure out just what it is. Any help would be greatly appreciated. Thanks!

CSS in question:

.aligncenter, div.aligncenter, .post p div.aligncenter { display: block; margin-left: auto; margin-right: auto; }

HTML in question:

<p><div class="aligncenter"><img src="http://justincox.com/wordpress/wp-content/uploads/2009/12/azumi.png" alt="Azumi" border="0" width="500" height="326" /></div></p>

Full source: http://justincox.com/2009/year-in-movies-December/

Wow, that was fast. Thank you. Adding width: inherit; fixed the issue. Knew it was something simple. Thanks again.

Auto margins only work when a width has been set.

The value “inherit” isn’t supported ihn IE7< except for a few properties

Setting an actual width (aka 500px or whatever) would work better.