Index: /Users/dschoon/dev/Projects/jQuery/trunk/jquery/src/core.js
===================================================================
--- /Users/dschoon/dev/Projects/jQuery/trunk/jquery/src/core.js	(revision 5510)
+++ /Users/dschoon/dev/Projects/jQuery/trunk/jquery/src/core.js	(working copy)
@@ -716,24 +716,26 @@
 		var name, i = 0, length = object.length;
 		
 		if ( args ) {
-			if ( length == undefined ) {
+			if ( object instanceof Array ) 
+				for ( ; i < length; )
+					if ( callback.apply( object[ i++ ], args ) === false )
+						break;
+			else {
 				for ( name in object )
 					if ( callback.apply( object[ name ], args ) === false )
 						break;
-			} else
-				for ( ; i < length; )
-					if ( callback.apply( object[ i++ ], args ) === false )
-						break;
+			}
 
 		// A special, fast, case for the most common use of each
 		} else {
-			if ( length == undefined ) {
+			if ( object instanceof Array )
+				for ( var value = object[0]; 
+					i < length && callback.call( value, i, value ) !== false; value = object[++i] ){}
+			else {
 				for ( name in object )
 					if ( callback.call( object[ name ], name, object[ name ] ) === false )
 						break;
-			} else
-				for ( var value = object[0]; 
-					i < length && callback.call( value, i, value ) !== false; value = object[++i] ){}
+			}
 		}
 
 		return object;