Index: lnt/external/stats/stats.py
===================================================================
--- lnt/external/stats/stats.py
+++ lnt/external/stats/stats.py
@@ -235,7 +235,7 @@
 ############# DISPATCH CODE ##############
 
 
-class Dispatch:
+class Dispatch(object):
     """
 The Dispatch class, care of David Ascher, allows different functions to
 be called depending on the argument types.  This way, there can be one
Index: lnt/server/config.py
===================================================================
--- lnt/server/config.py
+++ lnt/server/config.py
@@ -9,7 +9,7 @@
 import lnt.server.db.v4db
 
 
-class EmailConfig:
+class EmailConfig(object):
     @staticmethod
     def from_data(data):
         # The email to field can either be a string, or a list of tuples of
@@ -37,7 +37,7 @@
                 return address
 
 
-class DBInfo:
+class DBInfo(object):
     @staticmethod
     def from_data(baseDir, config_data, default_email_config,
                   default_baseline_revision):
@@ -88,7 +88,7 @@
         return "DBInfo(" + self.path + ")"
 
 
-class Config:
+class Config(object):
     @staticmethod
     def from_data(path, data):
         # Paths are resolved relative to the absolute real path of the
Index: lnt/server/db/regression.py
===================================================================
--- lnt/server/db/regression.py
+++ lnt/server/db/regression.py
@@ -7,7 +7,7 @@
 from lnt.testing.util.commands import timed
 
 
-class RegressionState:
+class RegressionState(object):
     # A new regression, not approved by the user yet.
     DETECTED = 0
     # Approved, but waiting for cooldown.
Index: lnt/server/reporting/analysis.py
===================================================================
--- lnt/server/reporting/analysis.py
+++ lnt/server/reporting/analysis.py
@@ -50,7 +50,7 @@
     return stats.geometric_mean(values) - MIN_VALUE_PRECISION
 
 
-class ComparisonResult:
+class ComparisonResult(object):
     """A ComparisonResult is ultimatly responsible for determining if a test
     improves, regresses or does not change, given some new and old data."""
 
@@ -99,7 +99,7 @@
             self.stddev = None
             self.MAD = None
 
-        self.stddev_mean = None  # Only calculate this if needed.
+        self.__set_stddev_mean(None)  # Only calculate this if needed.
         self.failed = cur_failed
         self.prev_failed = prev_failed
         self.samples = samples
@@ -108,13 +108,17 @@
         self.confidence_lv = confidence_lv
         self.bigger_is_better = bigger_is_better
 
-    @property
-    def stddev_mean(self):
+    def __get_stddev_mean(self):
         """The mean around stddev for current sampples. Cached after first call.
         """
-        if not self.stddev_mean:
-            self.stddev_mean = stats.mean(self.samples)
-        return self.stddev_mean
+        if not self.__stddev_mean:
+            self.__stddev_mean = stats.mean(self.samples)
+        return self.__stddev_mean
+
+    def __set_stddev_mean(self, value):
+        self.__stddev_mean = value
+
+    stddev_mean = property(__get_stddev_mean, __set_stddev_mean)
 
     def __repr__(self):
         """Print this ComparisonResult's constructor.
Index: lnt/server/reporting/report.py
===================================================================
--- lnt/server/reporting/report.py
+++ lnt/server/reporting/report.py
@@ -56,7 +56,7 @@
 
 # Helper classes to make the sparkline chart construction easier in the jinja
 # template.
-class RunResult:
+class RunResult(object):
     def __init__(self, comparisonResult):
         self.cr = comparisonResult
         self.hash = self.cr.cur_hash
@@ -64,7 +64,7 @@
         if self.samples is None:
             self.samples = []
 
-class RunResults:
+class RunResults(object):
     """
     RunResults contains pre-processed data to easily construct the HTML for
     a single row in the results table, showing how one test on one board
Index: lnt/server/ui/util.py
===================================================================
--- lnt/server/ui/util.py
+++ lnt/server/ui/util.py
@@ -135,7 +135,7 @@
     return tuple([av * t_ + bv * t for av, bv in zip(a, b)])
 
 
-class PctCell:
+class PctCell(object):
     # Color levels
     kNeutralColor = (1, 1, 1)
     kNegativeColor = (0, 1, 0)
@@ -302,7 +302,7 @@
     return val
 
 
-class PrecomputedCR():
+class PrecomputedCR(object):
     """Make a thing that looks like a comprison result, that is derived
     from a field change."""
     previous = 0
Index: lnt/testing/__init__.py
===================================================================
--- lnt/testing/__init__.py
+++ lnt/testing/__init__.py
@@ -31,7 +31,7 @@
     return t.strftime('%Y-%m-%d %H:%M:%S')
 
 
-class Report:
+class Report(object):
     """Information on a single testing run.
 
     In the LNT test model, every test run should define exactly one
@@ -102,7 +102,7 @@
                               sort_keys=True, indent=indent, encoding='latin-1')
 
 
-class Machine:
+class Machine(object):
     """Information on the machine the test was run on.
 
     The info dictionary can be used to describe additional information
@@ -143,7 +143,7 @@
                     'Info': self.info}
 
 
-class Run:
+class Run(object):
     """Information on the particular test run.
 
     At least one parameter must be supplied and is used as ordering
@@ -228,7 +228,7 @@
                     'Info': info}
 
 
-class Test:
+class Test(object):
     """Information on a particular test in the run and its associated
     samples.
 
@@ -292,7 +292,7 @@
         return d
 
 
-class TestSamples:
+class TestSamples(object):
     """Information on a given test and its associated samples data.
 
     Samples data must all relate to the same metric. When several
@@ -349,7 +349,7 @@
                                                 self.info)
 
 
-class MetricSamples:
+class MetricSamples(object):
     """Samples data for a given metric of a given test.
 
     An arbitrary number of samples for a given metric is allowed for
Index: lnt/util/multidict.py
===================================================================
--- lnt/util/multidict.py
+++ lnt/util/multidict.py
@@ -1,4 +1,4 @@
-class multidict:
+class multidict(object):
     def __init__(self, elts=()):
         self.data = {}
         for key, value in elts: