diff -r 6c5245427ccb Lib/distutils/command/sdist.py
--- a/Lib/distutils/command/sdist.py	Fri Apr 15 17:55:36 2011 -0700
+++ b/Lib/distutils/command/sdist.py	Sun Apr 17 13:19:05 2011 +0800
@@ -363,6 +363,8 @@
 
         content = self.filelist.files[:]
         content.insert(0, '# file GENERATED by distutils, do NOT edit')
+        for line in content:
+            line.replace('\\','/')
         self.execute(file_util.write_file, (self.manifest, content),
                      "writing manifest file '%s'" % self.manifest)
 
diff -r 6c5245427ccb Lib/distutils/tests/test_sdist.py
--- a/Lib/distutils/tests/test_sdist.py	Fri Apr 15 17:55:36 2011 -0700
+++ b/Lib/distutils/tests/test_sdist.py	Sun Apr 17 13:19:05 2011 +0800
@@ -419,6 +419,24 @@
             f.close()
 
         self.assertEqual(manifest, ['README.manual'])
+        
+    def test_manifest_sep(self):
+        # http://bugs.python.org/issue828450
+        # check if every file path line in MANIFEST takes '/' as path separator
+        # thus Unix can read MANIFEST file generated by Windows without any problem
+        
+        dist, cmd =  self.get_cmd()
+        cmd.ensure_finalized()
+        cmd.run()
+        
+        f = open(cmd.manifest)
+        try:
+            manifest = [line.strip() for line in f.read().split('\n')
+                        if line.strip() != '']
+            for line in manifest:
+                self.assertNotIn('\\', line)
+        finally:
+            f.close()
 
 def test_suite():
     return unittest.makeSuite(SDistTestCase)