diff --git a/min/lib/Minify/YUICompressor.php b/min/lib/Minify/YUICompressor.php
index cd93b0e..c5bd8a1 100644
--- a/min/lib/Minify/YUICompressor.php
+++ b/min/lib/Minify/YUICompressor.php
@@ -90,8 +90,11 @@ class Minify_YUICompressor {
             throw new Exception('Minify_YUICompressor : could not create temp file.');
         }
         file_put_contents($tmpFile, $content);
-        exec(self::_getCmd($options, $type, $tmpFile), $output);
+        exec(self::_getCmd($options, $type, $tmpFile), $output, $result_code);
         unlink($tmpFile);
+        if ($result_code != 0) {
+            throw new Exception('Minify_YUICompressor : YUI compressor execution failed.');
+        }
         return implode("\n", $output);
     }
     
@@ -131,6 +134,9 @@ class Minify_YUICompressor {
         if (! is_file(self::$jarFile)) {
             throw new Exception('Minify_YUICompressor : $jarFile('.self::$jarFile.') is not a valid file.');
         }
+        if (! is_executable(self::$jarFile)) {
+            throw new Exception('Minify_YUICompressor : $jarFile('.self::$jarFile.') is not executable.');
+        }
         if (! is_dir(self::$tempDir)) {
             throw new Exception('Minify_YUICompressor : $tempDir('.self::$tempDir.') is not a valid direcotry.');
         }