$this->base_url = preg_replace("/(.+?)\/*$/", "\\1/",  $this->base_url);

changed to

$this->base_url = rtrim($this->base_url, '/') .'/';
diff --git a/system/libraries/Pagination.php b/system/libraries/Pagination.php
index 8ea0dab..c5c718d 100644
--- a/system/libraries/Pagination.php
+++ b/system/libraries/Pagination.php
@@ -146,8 +146,8 @@
 		$end   = (($this->cur_page + $this->num_links) < $num_pages) ? $this->cur_page + $this->num_links : $num_pages;

 

 		// Add a trailing slash to the base URL if needed

-		$this->base_url = preg_replace("/(.+?)\/*$/", "\\1/",  $this->base_url);

-		

+		$this->base_url = rtrim($this->base_url, '/') .'/';

+

   		// And here we go...

 		$output = '';