Avoid double-slashed on the base_url by only slashing index_page if it is actually set.
diff --git a/system/core/Config.php b/system/core/Config.php
index 8ecfba7..7f50191 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -229,8 +229,9 @@
 				$uri = implode('/', $uri);
 			}
 
+			$index = $this->item('index_page') == '' ? '' : $this->slash_item('index_page');
 			$suffix = ($this->item('url_suffix') == FALSE) ? '' : $this->item('url_suffix');
-			return $this->slash_item('base_url').$this->slash_item('index_page').trim($uri, '/').$suffix;
+			return $this->slash_item('base_url').$index.trim($uri, '/').$suffix;
 		}
 		else
 		{