diff --git a/cake/libs/model/behaviors/tree.php b/cake/libs/model/behaviors/tree.php
index 844db147e..8cf3799c8 100644
--- a/cake/libs/model/behaviors/tree.php
+++ b/cake/libs/model/behaviors/tree.php
@@ -769,6 +769,9 @@ class TreeBehavior extends ModelBehavior {
 			if (is_null($instance[$model->alias][$left]) || is_null($instance[$model->alias][$right])) {
 				$errors[] = array('node', $instance[$model->alias][$model->primaryKey],
 					'has invalid left or right values');
+			} elseif ($instance[$model->alias][$left] == $instance[$model->alias][$right]){
+				$errors[] = array('node', $instance[$model->alias][$model->primaryKey],
+					'left and right values identical');
 			} elseif ($instance[$model->alias][$parent]) {
 				if (!$instance['VerifyParent'][$model->primaryKey]) {
 					$errors[] = array('node', $instance[$model->alias][$model->primaryKey],
diff --git a/cake/tests/cases/libs/model/behaviors/tree.test.php b/cake/tests/cases/libs/model/behaviors/tree.test.php
index e33dec56a..6bf12aeb6 100644
--- a/cake/tests/cases/libs/model/behaviors/tree.test.php
+++ b/cake/tests/cases/libs/model/behaviors/tree.test.php
@@ -415,6 +415,30 @@ class NumberTreeCase extends CakeTestCase {
 		$result = $this->NumberTree->verify();
 		$this->assertIdentical($result, true);
 	}
+/**
+ * Reproduces a situation where a single node has lft=rght, and all other lft and rght fields follow sequentially
+ * 
+ * @access public
+ * @return void
+ */
+	function testDetectEqualLftsRghts() {
+		$this->NumberTree =& new NumberTree();
+		$this->NumberTree->initialize(1, 3);
+
+		$result = $this->NumberTree->findByName('1.1');
+		$this->NumberTree->updateAll(array('rght' => $result['NumberTree']['lft']), array('id' => $result['NumberTree']['id']));
+		$this->NumberTree->updateAll(array('lft' => 'lft-1'), array('lft >' => $result['NumberTree']['lft']));
+		$this->NumberTree->updateAll(array('rght' => 'rght-1'), array('rght >' => $result['NumberTree']['lft']));
+
+		$result = $this->NumberTree->verify();
+		$this->assertNotIdentical($result, true);
+
+		$result = $this->NumberTree->recover();
+		$this->assertTrue($result);
+
+		$result = $this->NumberTree->verify();
+		$this->assertTrue($result);
+	}
 /**
  * testAddOrphan method
  *