Page centered in Firefox, left aligned in IE?

My site is center aligned in firefox due to the following CSS:
#page {
background:url(images/body.png)
repeat-y center;
text-align:left;
width:760px;
margin:20px auto;
}

In IE, however, the entire page is left aligned. I have tried messing around with some IE CSS hacks, and this is the closest I’ve come to a desirable effect:
/* Start Hide from non-IE/Win */
* html #page {
margin-left:20%;
}
/* End Hide from non-IE/Win */

However, this only looks good at 1280×1024 desktop resolution. I bring it over to my second monitor, which runs at 1024×768, and the page seems to favor the right side of the window. Now, I know why this is. But what I don’t understand is why IE has such a hard time centering it. margin:20px auto; should do the trick, just as it does in IE.

If there is some way of getting IE to center the page, that would be beautiful. If not, however, a left-aligned page isn’t all that bad.