Fixed boxModel support - is now computed with feature detection, rather than sniffing.

Makefile

@@ -10,9 +10,9 @@ PLUG_DIR = ../plugins
 
 BASE_FILES = ${SRC_DIR}/core.js\
 	${SRC_DIR}/data.js\
-	${SRC_DIR}/support.js\
 	${SRC_DIR}/selector.js\
 	${SRC_DIR}/event.js\
+	${SRC_DIR}/support.js\
 	${SRC_DIR}/ajax.js\
 	${SRC_DIR}/fx.js\
 	${SRC_DIR}/offset.js\

src/core.js

@@ -1146,9 +1146,6 @@ jQuery.browser = {
 	mozilla: /mozilla/.test( userAgent ) && !/(compatible|webkit)/.test( userAgent )
 };
 
-// Check to see if the W3C box model is being used
-jQuery.boxModel = !jQuery.browser.msie || document.compatMode == "CSS1Compat";
-
 jQuery.each({
 	parent: function(elem){return elem.parentNode;},
 	parents: function(elem){return jQuery.dir(elem,"parentNode");},

src/support.js

@@ -53,7 +53,8 @@
 
 		// Will be defined later
 		scriptEval: false,
-		noCloneEvent: true
+		noCloneEvent: true,
+		boxModel: null
 	};
 	
 	script.type = "text/javascript";
@@ -83,6 +84,17 @@
 		div.cloneNode(true).fireEvent("onclick");
 	}
 
+	// Figure out if the W3C box model works as expected
+	// document.body must exist before we can do this
+	jQuery(function(){
+		var div = document.createElement("div");
+		div.style.width = "1px";
+		div.style.paddingLeft = "1px";
+
+		document.body.appendChild( div );
+		jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
+		document.body.removeChild( div );
+	});
 })();
 
 var styleFloat = jQuery.support.cssFloat ? "cssFloat" : "styleFloat";