               unit = attribute.width.match(/[px|%]+/)[0]
 
               if unit is '%'
-                attribute.displayWidth = value / 100 * @el.width()
+                attribute.displayWidth = value / 100 * availableWidth
               else
                 attribute.displayWidth = value
             @headers.push attribute

            if attributeName is "#{item}_id" || attributeName is "#{item}_ids"
              headerFound = true
              if @headerWidth[attribute.name]
                attribute.displayWidth = @headerWidth[attribute.name] * @availableWidth
              else if !attribute.width
                attribute.displayWidth = @baseColWidth
              else

            # e.g. column: owner
            headerFound = true
            if @headerWidth[attribute.name]
              attribute.displayWidth = @headerWidth[attribute.name] * availableWidth
            else if !attribute.width
              attribute.displayWidth = @baseColWidth
            else
