diff --git a/core/dbobjectsearch.class.php b/core/dbobjectsearch.class.php
index 82a424834..b6373233f 100644
--- a/core/dbobjectsearch.class.php
+++ b/core/dbobjectsearch.class.php
@@ -72,11 +72,11 @@ class DBObjectSearch
 	}
 
 	/**
-	 * Perform a deep clone (as opposed to "clone" which does copy a reference to the underlying objects
+	 * Perform a deep clone (as opposed to "clone" which does copy a reference to the underlying objects)
 	 **/	 	
 	public function DeepClone()
 	{
-		return unserialize(serialize($this));
+		return unserialize(serialize($this)); // Beware this serializes/unserializes the search and its parameters as well
 	}
 
 	public function AllowAllData() {$this->m_bAllowAllData = true;}
diff --git a/core/dbobjectset.class.php b/core/dbobjectset.class.php
index ab76309d0..7ea951659 100644
--- a/core/dbobjectset.class.php
+++ b/core/dbobjectset.class.php
@@ -112,7 +112,17 @@ class DBObjectSet
 		$this->m_oSQLResult = null;
 	}
 
-
+	/**
+	 * Called when unserializing a DBObjectSet
+	 */
+	public function __wakeup()
+	{
+		$this->m_iNumTotalDBRows = null; // Total number of rows for the query without LIMIT. null if unknown yet
+		$this->m_iNumLoadedDBRows = 0; // Total number of rows LOADED in $this->m_oSQLResult via a SQL query. 0 by default
+		$this->m_bLoaded = false; // true when the filter has been used OR the set is built step by step (AddObject...)
+		$this->m_iCurrRow = 0;
+		$this->m_oSQLResult = null;
+	}
 	/**
 	 * Specify the subset of attributes to load (for each class of objects) before performing the SQL query for retrieving the rows from the DB
 	 *