diff --git a/migrate/versioning/genmodel.py b/migrate/versioning/genmodel.py
index 3c63a0d..1715175 100644
--- a/migrate/versioning/genmodel.py
+++ b/migrate/versioning/genmodel.py
@@ -128,7 +128,7 @@ class ModelGenerator(object):
         decls = ['from migrate.changeset import schema',
                  'meta = MetaData()']
         for table in self.diff.tablesMissingInModel + \
-                self.diff.tablesMissingInDatabase  + \
+                self.diff.tablesMissingInDatabase + \
                 self.diff.tablesWithDiff:
             decls.extend(self.getTableDefn(table))
 
diff --git a/migrate/versioning/schemadiff.py b/migrate/versioning/schemadiff.py
index 80a6085..bd22f92 100644
--- a/migrate/versioning/schemadiff.py
+++ b/migrate/versioning/schemadiff.py
@@ -84,7 +84,7 @@ class SchemaDiff(object):
             if modelName in self.excludeTables:
                 continue
             reflectedTable = self.reflected_model.tables.get(modelName, None)
-            if reflectedTable:
+            if reflectedTable is not None:
                 # Table exists.
                 pass
             else:
@@ -96,14 +96,14 @@ class SchemaDiff(object):
             if reflectedName in self.excludeTables:
                 continue
             modelTable = self.model.tables.get(reflectedName, None)
-            if modelTable:
+            if modelTable is not None:
                 # Table exists.
 
                 # Find missing columns in database.
                 for modelCol in modelTable.columns:
                     databaseCol = reflectedTable.columns.get(modelCol.name,
                                                              None)
-                    if databaseCol:
+                    if databaseCol is not None:
                         pass
                     else:
                         self.storeColumnMissingInDatabase(modelTable, modelCol)
@@ -114,7 +114,7 @@ class SchemaDiff(object):
                     # TODO: no test coverage here?   (mrb)
                     
                     modelCol = modelTable.columns.get(databaseCol.name, None)
-                    if modelCol:
+                    if modelCol is not None:
                         # Compare attributes of column.
                         modelDecl = \
                             get_column_specification(modelCol)
diff --git a/migrate/versioning/version.py b/migrate/versioning/version.py
index 3561b48..11f7aa0 100644
--- a/migrate/versioning/version.py
+++ b/migrate/versioning/version.py
@@ -178,12 +178,15 @@ class Version(object):
     SQL_FILENAME = re.compile(r'^(\d+)_([^_]+)_([^_]+).sql')
 
     def _add_script_sql(self, path):
-        match = self.SQL_FILENAME.match(os.path.basename(path))
+        basename = os.path.basename(path)
+        match = self.SQL_FILENAME.match(basename)
 
         if match:
             version, dbms, op = match.group(1), match.group(2), match.group(3)
         else:
-            raise exceptions.ScriptError("Invalid SQL script name %s" % path)
+            raise exceptions.ScriptError(
+                "Invalid SQL script name %s " % basename + \
+                "(needs to be ###_database_operation.sql)")
 
         # File the script into a dictionary
         self.sql.setdefault(dbms, {})[op] = script.SqlScript(path)