diff --git a/core/misc/tabledrag.js b/core/misc/tabledrag.js
index c3a0f5a..52ad4dd 100644
--- a/core/misc/tabledrag.js
+++ b/core/misc/tabledrag.js
@@ -266,30 +266,36 @@
    */
   Drupal.tableDrag.prototype.initColumns = function () {
     var $table = this.$table;
-    var hidden;
-    var cell;
+    var hasHiddenColumn;
+    var $cells;
     var columnIndex;
+
+    function isHiddenColumn(element, index, array) {
+      if (element.hidden) {
+        var td = 'td.' + element.target;
+        var th = 'th.' + element.target;
+        $cells = $table.find(td, th);
+        if ($cells.length) {
+          return true;
+        }
+      }
+    }
+
     for (var group in this.tableSettings) {
       if (this.tableSettings.hasOwnProperty(group)) {
 
-        // Find the first field in this group.
-        for (var d in this.tableSettings[group]) {
-          if (this.tableSettings[group].hasOwnProperty(d)) {
-            var field = $table.find('.' + this.tableSettings[group][d].target).eq(0);
-            if (field.length && this.tableSettings[group][d].hidden) {
-              hidden = this.tableSettings[group][d].hidden;
-              cell = field.closest('td');
-              break;
-            }
-          }
-        }
+        // tests whether some element with target class in this group.
+        hasHiddenColumn = this.tableSettings[group].some(isHiddenColumn);
 
         // Mark the column containing this field so it can be hidden.
-        if (hidden && cell[0]) {
+        if (hasHiddenColumn) {
+
           // Add 1 to our indexes. The nth-child selector is 1 based, not 0
           // based. Match immediate children of the parent element to allow
           // nesting.
-          columnIndex = cell.parent().find('> td').index(cell.get(0)) + 1;
+          columnIndex = $cells.index() + 1;
+          // Check whether the matching cell is in a row containing colspans.
+          // If so, adjust columnIndex accordingly.
           $table.find('> thead > tr, > tbody > tr, > tr').each(this.addColspanClass(columnIndex));
         }
       }
@@ -311,15 +317,24 @@
       // Get the columnIndex and adjust for any colspans in this row.
       var $row = $(this);
       var index = columnIndex;
-      var cells = $row.children();
+      var $cells = $row.children();
       var cell;
-      cells.each(function (n) {
+
+      var origIndex = index;
+      $cells.each(function (n) {
+        if (n < origIndex && this.colSpan && this.colSpan > 1) {
+          index += this.colSpan - 1;
+        }
+      });
+
+      $cells.each(function (n) {
         if (n < index && this.colSpan && this.colSpan > 1) {
           index -= this.colSpan - 1;
         }
       });
+
       if (index > 0) {
-        cell = cells.filter(':nth-child(' + index + ')');
+        cell = $cells.filter(':nth-child(' + index + ')');
         if (cell[0].colSpan && cell[0].colSpan > 1) {
           // If this cell has a colspan, mark it so we can reduce the colspan.
           cell.addClass('tabledrag-has-colspan');
@@ -1341,7 +1356,7 @@
       }
     }
 
-    return {'min': minIndent, 'max': maxIndent};
+    return {min: minIndent, max: maxIndent};
   };
 
   /**