Changed a few strstr to strpos for consistency w performance guidelines and to mirror EE2.
diff --git a/system/helpers/download_helper.php b/system/helpers/download_helper.php
index 638ebaa..eac024f 100644
--- a/system/helpers/download_helper.php
+++ b/system/helpers/download_helper.php
@@ -71,7 +71,7 @@
 		}
 	
 		// Generate the server headers
-		if (strstr($_SERVER['HTTP_USER_AGENT'], "MSIE"))
+		if (strpos($_SERVER['HTTP_USER_AGENT'], "MSIE") !== FALSE)
 		{
 			header('Content-Type: "'.$mime.'"');
 			header('Content-Disposition: attachment; filename="'.$filename.'"');