diff -r 7794f1e8576e Lib/test/test_msilib.py
--- a/Lib/test/test_msilib.py	Sat May 28 20:02:44 2011 +0800
+++ b/Lib/test/test_msilib.py	Sat May 28 22:21:54 2011 +0800
@@ -1,8 +1,25 @@
 """ Test suite for the code in msilib """
 import unittest
-import os
-from test.support import run_unittest, import_module
-msilib = import_module('msilib')
+from test import support
+import datetime
+
+msilib = support.import_module('msilib')
+import msilib.schema
+
+
+LAST_PRINTED_DATE = datetime.datetime(2011, 5, 30, 10, 55, 56)
+
+def create_temp_db():
+    "Create a very simple database to open"
+    path = support.TESTFN + ".msi"
+    db = msilib.init_database(
+        path, msilib.schema, "Python Tests", "product_code", "1.0", "PSF")
+    db.Commit()
+    db = None
+    return path
+
+TEST_DB_PATH = create_temp_db()
+
 
 class Test_make_id(unittest.TestCase):
     #http://msdn.microsoft.com/en-us/library/aa369212(v=vs.85).aspx
@@ -39,8 +56,39 @@
             msilib.make_id(".s\x82o?*+rt"), "_.s_o___rt")
 
 
+class TestSummaryInformation(unittest.TestCase):
+
+    def tearDown(self):
+        self.db = None
+
+    def test_get_property_count(self):
+        self.db = msilib.OpenDatabase(TEST_DB_PATH, msilib.MSIDBOPEN_READONLY)
+        si = self.db.GetSummaryInformation(0)
+        self.assertEqual(si.GetPropertyCount(), 8)
+
+    def test_get_property(self):
+        self.db = msilib.OpenDatabase(TEST_DB_PATH, msilib.MSIDBOPEN_READONLY)
+        si = self.db.GetSummaryInformation(0)
+        self.assertEqual(si.GetProperty(msilib.PID_AUTHOR), b'PSF')
+        self.assertEqual(si.GetProperty(msilib.PID_WORDCOUNT), 2)
+        #self.assertEqual(
+        #    si.GetProperty(msilib.PID_LASTPRINTED), LAST_PRINTED_DATE)
+
+    def test_set_property(self):
+        self.db = msilib.OpenDatabase(TEST_DB_PATH, msilib.MSIDBOPEN_TRANSACT)
+        si = self.db.GetSummaryInformation(20)
+        si.SetProperty(msilib.PID_AUTHOR, 'PS2')
+        si.SetProperty(msilib.PID_WORDCOUNT, 1)
+        si.Persist()
+        si = None
+        self.db.Commit()
+        si = self.db.GetSummaryInformation(0)
+        self.assertEqual(si.GetProperty(msilib.PID_AUTHOR), b'PS2')
+        self.assertEqual(si.GetProperty(msilib.PID_WORDCOUNT), 1)
+
+
 def test_main():
-    run_unittest(__name__)
+    support.run_unittest(__name__)
 
 if __name__ == '__main__':
     test_main()
diff -r 7794f1e8576e PC/_msi.c
--- a/PC/_msi.c	Sat May 28 20:02:44 2011 +0800
+++ b/PC/_msi.c	Sat May 28 22:21:54 2011 +0800
@@ -547,7 +547,11 @@
             &fval, sval, &ssize);
     }
 
-    switch(type) {
+	if (status != ERROR_SUCCESS){
+        return msierror(status);
+    }
+
+	switch(type) {
         case VT_I2: case VT_I4:
             return PyLong_FromLong(ival);
         case VT_FILETIME: