Fixed Upload bug that would break when files and images were both included on an allowed filetype list in the wrong order: http://codeigniter.com/bug_tracker/bug/11552/
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index 3131469..0e71aee 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -578,7 +578,7 @@
 			$mime = $this->mimes_types(strtolower($val));
 
 			// Images get some additional checks
-			if (in_array($val, $image_types))
+			if ($this->file_ext == '.' . $val &&  in_array($val, $image_types))
 			{
 				if (getimagesize($this->file_temp) === FALSE)
 				{