diff --git a/calendar/templates/default/header.inc.php b/calendar/templates/default/header.inc.php
index db36757d53..49216a8caf 100755
--- a/calendar/templates/default/header.inc.php
+++ b/calendar/templates/default/header.inc.php
@@ -176,7 +176,7 @@
 			);
 		}
 		$memberships = $GLOBALS['phpgw']->accounts->membership($GLOBALS['phpgw_info']['user']['account_id']);
-		while(list($key,$group_info) = each($memberships))
+		while($memberships != False && list($key,$group_info) = each($memberships))
 		{
 			$account_perms = $GLOBALS['phpgw']->acl->get_ids_for_location($group_info['account_id'],PHPGW_ACL_READ,'calendar');
 			while($account_perms && list($key,$group_id) = each($account_perms))
diff --git a/calendar/templates/idsociety/header.inc.php b/calendar/templates/idsociety/header.inc.php
index db36757d53..49216a8caf 100755
--- a/calendar/templates/idsociety/header.inc.php
+++ b/calendar/templates/idsociety/header.inc.php
@@ -176,7 +176,7 @@
 			);
 		}
 		$memberships = $GLOBALS['phpgw']->accounts->membership($GLOBALS['phpgw_info']['user']['account_id']);
-		while(list($key,$group_info) = each($memberships))
+		while($memberships != False && list($key,$group_info) = each($memberships))
 		{
 			$account_perms = $GLOBALS['phpgw']->acl->get_ids_for_location($group_info['account_id'],PHPGW_ACL_READ,'calendar');
 			while($account_perms && list($key,$group_id) = each($account_perms))
diff --git a/calendar/templates/justweb/header.inc.php b/calendar/templates/justweb/header.inc.php
index db36757d53..49216a8caf 100755
--- a/calendar/templates/justweb/header.inc.php
+++ b/calendar/templates/justweb/header.inc.php
@@ -176,7 +176,7 @@
 			);
 		}
 		$memberships = $GLOBALS['phpgw']->accounts->membership($GLOBALS['phpgw_info']['user']['account_id']);
-		while(list($key,$group_info) = each($memberships))
+		while($memberships != False && list($key,$group_info) = each($memberships))
 		{
 			$account_perms = $GLOBALS['phpgw']->acl->get_ids_for_location($group_info['account_id'],PHPGW_ACL_READ,'calendar');
 			while($account_perms && list($key,$group_id) = each($account_perms))
diff --git a/calendar/templates/verdilak/header.inc.php b/calendar/templates/verdilak/header.inc.php
index db36757d53..49216a8caf 100755
--- a/calendar/templates/verdilak/header.inc.php
+++ b/calendar/templates/verdilak/header.inc.php
@@ -176,7 +176,7 @@
 			);
 		}
 		$memberships = $GLOBALS['phpgw']->accounts->membership($GLOBALS['phpgw_info']['user']['account_id']);
-		while(list($key,$group_info) = each($memberships))
+		while($memberships != False && list($key,$group_info) = each($memberships))
 		{
 			$account_perms = $GLOBALS['phpgw']->acl->get_ids_for_location($group_info['account_id'],PHPGW_ACL_READ,'calendar');
 			while($account_perms && list($key,$group_id) = each($account_perms))