diff --git a/src/components/main/layout/block.rs b/src/components/main/layout/block.rs
index 0dee3e1c45f..03e9c62dcf7 100644
--- a/src/components/main/layout/block.rs
+++ b/src/components/main/layout/block.rs
@@ -106,8 +106,9 @@ impl BlockFlowData {
            these widths will not include child elements, just padding etc. */
         self.box.map(|&box| {
             //Can compute border width here since it doesn't depend on anything
+            let style = box.style();
             do box.with_model |model| {
-                model.compute_borders(box.style())
+                model.compute_borders(style)
             }
             min_width = min_width.add(&box.get_min_width(ctx));
             pref_width = pref_width.add(&box.get_pref_width(ctx));
@@ -184,17 +185,18 @@ impl BlockFlowData {
         let mut x_offset = Au(0);
 
         self.box.map(|&box| {
+            let style = box.style();
             do box.with_model |model| {
-                model.compute_padding(box.style(), remaining_width);
+                model.compute_padding(style, remaining_width);
 
                 let available_width = remaining_width - model.noncontent_width();
 
-                let margin_top = MaybeAuto::from_margin(box.style().margin_top()).spec_or_default(Au(0));
-                let margin_bottom = MaybeAuto::from_margin(box.style().margin_bottom()).spec_or_default(Au(0));
+                let margin_top = MaybeAuto::from_margin(style.margin_top()).spec_or_default(Au(0));
+                let margin_bottom = MaybeAuto::from_margin(style.margin_bottom()).spec_or_default(Au(0));
 
-                let (width, margin_left, margin_right) = (MaybeAuto::from_width(box.style().width()),
-                    MaybeAuto::from_margin(box.style().margin_left()),
-                    MaybeAuto::from_margin(box.style().margin_right()));
+                let (width, margin_left, margin_right) = (MaybeAuto::from_width(style.width()),
+                    MaybeAuto::from_margin(style.margin_left()),
+                    MaybeAuto::from_margin(style.margin_right()));
 
                 let (width, margin_left, margin_right) = 
                     self.compute_horiz(width, margin_left, margin_right, available_width);
diff --git a/src/components/main/layout/box.rs b/src/components/main/layout/box.rs
index 2b825ba67a1..3cfeaa9c10e 100644
--- a/src/components/main/layout/box.rs
+++ b/src/components/main/layout/box.rs
@@ -8,7 +8,7 @@ use css::node_style::StyledNode;
 use layout::context::LayoutContext;
 use layout::display_list_builder::{DisplayListBuilder, ExtraDisplayListData, ToGfxColor};
 use layout::flow::FlowContext;
-use layout::model::{BoxModel};
+use layout::model::BoxModel;
 use layout::text;
 
 use core::cell::Cell;
@@ -454,41 +454,15 @@ pub impl RenderBox {
         }
     }
 
-    fn compute_borders(&self){
-        do self.with_mut_base |base| {
-            base.model.compute_borders(base.node.style());
-        }
-    }
-
     fn get_noncontent_width(&self) -> Au {
         do self.with_imm_base |base| {
-            base.model.border.left + base.model.padding.left + base.model.border.right + 
-                base.model.padding.right
-        }
-    }
-
-    fn compute_width(&self,
-                     cb_width: Au,
-                     callback: &fn(MaybeAuto, MaybeAuto, MaybeAuto) -> (Au, Au, Au)) {
-        let computed_width = MaybeAuto::from_width(self.style().width());
-        let computed_margin_left = MaybeAuto::from_margin(self.style().margin_left());
-        let computed_margin_right = MaybeAuto::from_margin(self.style().margin_right());
-
-        let (used_width, used_margin_left, used_margin_right) = 
-            callback(computed_width, computed_margin_left, computed_margin_right);
-
-        let noncontent_width = self.get_noncontent_width();
-
-        do self.with_mut_base |base| {
-            base.model.margin.left = used_margin_left;
-            base.model.margin.right = used_margin_right;
-            base.position.size.width = used_width + noncontent_width;
-            base.position.origin.x = used_margin_left;
+            base.model.border.left + base.model.padding.left +
+            base.model.border.right + base.model.padding.right
         }
     }
 
     fn with_model<R>(&self, callback: &fn(&mut BoxModel) -> R) ->  R {
-        do self.with_imm_base |base| {
+        do self.with_mut_base |base| {
             callback(&mut base.model)
         }
     }
@@ -496,6 +470,15 @@ pub impl RenderBox {
     /// The box formed by the content edge as defined in CSS 2.1 § 8.1. Coordinates are relative to
     /// the owning flow.
     fn content_box(&self) -> Rect<Au> {
+        do self.with_imm_base |base| {
+            let origin = Point2D(base.position.origin.x +
+                                 base.model.border.left +
+                                 base.model.padding.left,
+                                 base.position.origin.y);
+            let size = Size2D(base.position.size.width - self.get_noncontent_width(), 
+                              base.position.size.height);
+            Rect(origin, size)
+        }
     }
 
     /// The box formed by the border edge as defined in CSS 2.1 § 8.1. Coordinates are relative to
diff --git a/src/components/main/layout/model.rs b/src/components/main/layout/model.rs
index 765ac12e5b1..cc38cffcc40 100644
--- a/src/components/main/layout/model.rs
+++ b/src/components/main/layout/model.rs
@@ -31,12 +31,12 @@ pub struct BoxModel {
 }
 
 /// Useful helper data type when computing values for blocks and positioned elements.
-pub enum MaybeAuto{
+pub enum MaybeAuto {
     Auto,
     Specified(Au),
 }
 
-impl MaybeAuto{
+impl MaybeAuto {
     pub fn from_margin(margin: CSSMargin) -> MaybeAuto{
         match margin {
             CSSMarginAuto => Auto,
diff --git a/src/support/css/rust-css b/src/support/css/rust-css
index 7a59bc7f27a..2f3f03cbafb 160000
--- a/src/support/css/rust-css
+++ b/src/support/css/rust-css
@@ -1 +1 @@
-Subproject commit 7a59bc7f27a2135668b9ca0f681f31a17dd68879
+Subproject commit 2f3f03cbafb88608d4f89216da7172d3b754fbef