diff --git a/phpBB/includes/acm/acm_main.php b/phpBB/includes/acm/acm_main.php
index 9e1d8349c1..a2d8bca4a3 100644
--- a/phpBB/includes/acm/acm_main.php
+++ b/phpBB/includes/acm/acm_main.php
@@ -28,7 +28,7 @@ class cache extends acm
 	{
 		global $db;
 
-		if ($config = $this->get('config'))
+		if (($config = $this->get('config')) !== false)
 		{
 			$sql = 'SELECT config_name, config_value
 				FROM ' . CONFIG_TABLE . '
@@ -79,7 +79,7 @@ class cache extends acm
 			return false;
 		}
 
-		if (!($censors = $this->get('word_censors')))
+		if (($censors = $this->get('word_censors')) === false)
 		{
 			$sql = 'SELECT word, replacement
 				FROM  ' . WORDS_TABLE;
@@ -104,7 +104,7 @@ class cache extends acm
 	*/
 	function obtain_icons(&$icons)
 	{
-		if (!($icons = $this->get('icons')))
+		if (($icons = $this->get('icons')) === false)
 		{
 			global $db;
 	
@@ -135,7 +135,7 @@ class cache extends acm
 	*/
 	function obtain_ranks(&$ranks)
 	{
-		if (!($ranks = $this->get('ranks')))
+		if (($ranks = $this->get('ranks')) === false)
 		{
 			global $db;
 	
@@ -176,7 +176,7 @@ class cache extends acm
 	*/
 	function obtain_attach_extensions(&$extensions, $forum_id = false)
 	{
-		if (!($extensions = $this->get('_extensions')))
+		if (($extensions = $this->get('_extensions')) === false)
 		{
 			global $db;
 	
@@ -257,7 +257,7 @@ class cache extends acm
 	*/
 	function obtain_bots(&$bots)
 	{
-		if (!($bots = $this->get('bots')))
+		if (($bots = $this->get('bots')) === false)
 		{
 			global $db;
 	
@@ -288,6 +288,7 @@ class cache extends acm
 			}
 			$result = $db->sql_query($sql);
 		
+			$bots = array();
 			while ($row = $db->sql_fetchrow($result))
 			{
 				$bots[] = $row;
@@ -317,7 +318,7 @@ class cache extends acm
 		{
 			$parsed_array = $this->get('_cfg_' . $key . '_' . $theme[$key . '_path']);
 
-			if (!$parsed_array)
+			if ($parsed_array === false)
 			{
 				$parsed_array = array();
 			}
diff --git a/phpBB/includes/acp/auth.php b/phpBB/includes/acp/auth.php
index ea4c664294..b1448b100c 100644
--- a/phpBB/includes/acp/auth.php
+++ b/phpBB/includes/acp/auth.php
@@ -38,6 +38,7 @@ class auth_admin extends auth
 			$result = $db->sql_query($sql);
 
 			$global = $local = 0;
+			$this->acl_options = array();
 			while ($row = $db->sql_fetchrow($result))
 			{
 				if ($row['is_global'])
diff --git a/phpBB/includes/auth.php b/phpBB/includes/auth.php
index 1dfd506bf8..f5e7610786 100644
--- a/phpBB/includes/auth.php
+++ b/phpBB/includes/auth.php
@@ -29,7 +29,7 @@ class auth
 		$this->acl = $this->cache = $this->acl_options = array();
 		$this->acl_forum_ids = false;
 
-		if (!($this->acl_options = $cache->get('acl_options')))
+		if (($this->acl_options = $cache->get('acl_options')) === false)
 		{
 			$sql = 'SELECT auth_option, is_global, is_local
 				FROM ' . ACL_OPTIONS_TABLE . '
@@ -37,6 +37,7 @@ class auth
 			$result = $db->sql_query($sql);
 
 			$global = $local = 0;
+			$this->acl_options = array();
 			while ($row = $db->sql_fetchrow($result))
 			{
 				if ($row['is_global'])
diff --git a/phpBB/includes/functions_module.php b/phpBB/includes/functions_module.php
index 9df7a53e08..942c542846 100644
--- a/phpBB/includes/functions_module.php
+++ b/phpBB/includes/functions_module.php
@@ -52,7 +52,7 @@ class p_master
 		$this->p_class = str_replace(array('.', '/', '\\'), '', basename($p_class));
 
 		// Get cached modules
-		if (!($this->module_cache = $cache->get('_modules_' . $this->p_class)))
+		if (($this->module_cache = $cache->get('_modules_' . $this->p_class)) === false)
 		{
 			// Get modules
 			$sql = 'SELECT *
diff --git a/phpBB/includes/session.php b/phpBB/includes/session.php
index 73d9c83374..200c4e3227 100644
--- a/phpBB/includes/session.php
+++ b/phpBB/includes/session.php
@@ -118,7 +118,7 @@ class session
 		$this->page = $this->extract_current_page($phpbb_root_path);
 		$this->page['page'] .= (isset($_POST['f'])) ? ((strpos($this->page['page'], '?') !== false) ? '&' : '?') . 'f=' . intval($_POST['f']) : '';
 
-		$this->cookie_data = array();
+		$this->cookie_data = array('u' => 0, 'k' => '');
 		if (isset($_COOKIE[$config['cookie_name'] . '_sid']) || isset($_COOKIE[$config['cookie_name'] . '_u']))
 		{
 			// Switch to request_var ... can this cause issues, can a _GET/_POST param