IE7 div centering with margin auto

I've been having some problems getting a div to center on a webpage.  All the websites I have visited said the fix was easy and gave me various forms of this as a solution:

<div style="text-align:center;">
<div style="text-align:left;">

Content goes here.

</div>

</div>

However, no matter what I put in my stylesheet I couldn't get it to work.  Turns out this fix has to be applied inline.  Putting it in a stylesheet doesn't work.  Once I got that figured out and grumbled for a bit everything worked great.