diff --git a/bootstrap-1.2.0.css b/bootstrap-1.2.0.css
index b7fe65e783..7a848a247c 100644
--- a/bootstrap-1.2.0.css
+++ b/bootstrap-1.2.0.css
@@ -6,7 +6,7 @@
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Designed and built with all the love in the world @twitter by @mdo and @fat.
- * Date: Fri Sep  2 15:07:03 PDT 2011
+ * Date: Fri Sep  2 20:59:16 PDT 2011
  */
 /* Reset.less
  * Props to Eric Meyer (meyerweb.com) for his CSS reset file. We're using an adapted version here	that cuts out some of the reset HTML elements we will never need here (i.e., dfn, samp, etc).
@@ -182,7 +182,8 @@ textarea {
 }
 .center-block {
   display: block;
-  margin: 0 auto;
+  margin-left: auto;
+  margin-right: auto;
 }
 .container {
   width: 940px;
@@ -393,10 +394,12 @@ body {
 }
 .container {
   width: 940px;
-  margin: 0 auto;
+  margin-left: auto;
+  margin-right: auto;
 }
 .container-fluid {
-  padding: 0 20px;
+  padding-left: 20px;
+  padding-right: 20px;
   zoom: 1;
   margin-bottom: 18px;
 }
diff --git a/bootstrap-1.2.0.min.css b/bootstrap-1.2.0.min.css
index 95b54405bb..e085351756 100644
--- a/bootstrap-1.2.0.min.css
+++ b/bootstrap-1.2.0.min.css
@@ -21,7 +21,7 @@ input[type="search"]::-webkit-search-decoration{-webkit-appearance:none;}
 textarea{overflow:auto;vertical-align:top;}
 .clearfix{zoom:1;}.clearfix:before,.clearfix:after{display:table;content:"";}
 .clearfix:after{clear:both;}
-.center-block{display:block;margin:0 auto;}
+.center-block{display:block;margin-left:auto;margin-right:auto;}
 .container{width:940px;margin:0 auto;zoom:1;margin-bottom:18px;}.container:before,.container:after{display:table;content:"";}
 .container:after{clear:both;}
 .btn.danger,.alert-message.danger,.btn.danger:hover,.alert-message.danger:hover,.btn.error,.alert-message.error,.btn.error:hover,.alert-message.error:hover,.btn.success,.alert-message.success,.btn.success:hover,.alert-message.success:hover,.btn.info,.alert-message.info,.btn.info:hover,.alert-message.info:hover{color:#ffffff;}
@@ -65,8 +65,8 @@ textarea{overflow:auto;vertical-align:top;}
 .row .offset-two-thirds{margin-left:660px;}
 html,body{background-color:#fff;}
 body{margin:0;font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px;font-weight:normal;line-height:18px;color:#808080;}
-.container{width:940px;margin:0 auto;}
-.container-fluid{padding:0 20px;zoom:1;margin-bottom:18px;}.container-fluid:before,.container-fluid:after{display:table;content:"";}
+.container{width:940px;margin-left:auto;margin-right:auto;}
+.container-fluid{padding-left:20px;padding-right:20px;zoom:1;margin-bottom:18px;}.container-fluid:before,.container-fluid:after{display:table;content:"";}
 .container-fluid:after{clear:both;}
 .container-fluid>.sidebar{float:left;width:220px;}
 .container-fluid>.content{min-width:700px;max-width:1180px;margin-left:240px;}
diff --git a/lib/preboot.less b/lib/preboot.less
index a922f569ce..d840ad1a61 100644
--- a/lib/preboot.less
+++ b/lib/preboot.less
@@ -70,7 +70,8 @@
 // Center-align a block level element
 .center-block {
 	display: block;
-  margin: 0 auto;
+  margin-left: auto;
+  margin-right: auto;
 }
 
 // Sizing shortcuts
diff --git a/lib/scaffolding.less b/lib/scaffolding.less
index 615e6be78d..b7c44e652a 100644
--- a/lib/scaffolding.less
+++ b/lib/scaffolding.less
@@ -73,13 +73,15 @@ body {
 
 // Container (centered, fixed-width layouts)
 .container {
-  width: 940px;
-  margin: 0 auto;
+  width: @siteWidth;
+  margin-left: auto;
+  margin-right: auto;
 }
 
 // Fluid layouts (left aligned, with sidebar, min- & max-width content)
 .container-fluid {
-  padding: 0 20px;
+  padding-left: 20px;
+  padding-right: 20px;
   .clearfix();
   > .sidebar {
     float: left;