diff --git a/GPy/examples/dimensionality_reduction.py b/GPy/examples/dimensionality_reduction.py
index 8b2b7a78..dcb0d400 100644
--- a/GPy/examples/dimensionality_reduction.py
+++ b/GPy/examples/dimensionality_reduction.py
@@ -138,6 +138,9 @@ def BGPLVM_oil(optimize=True, N=200, Q=10, num_inducing=15, max_f_eval=4e3, plot
 
     # optimize
     if optimize:
+        m.constrain_fixed('noise')
+        m.optimize('scg', messages=1, max_f_eval=100, gtol=.05)
+        m.constrain_positive('noise')
         m.optimize('scg', messages=1, max_f_eval=max_f_eval, gtol=.05)
 
     if plot:
diff --git a/GPy/models/mrd.py b/GPy/models/mrd.py
index 8ebff315..a31b044f 100644
--- a/GPy/models/mrd.py
+++ b/GPy/models/mrd.py
@@ -78,7 +78,7 @@ class MRD(Model):
         self.NQ = self.num_data * self.input_dim
         self.MQ = self.num_inducing * self.input_dim
 
-        model.__init__(self) # @UndefinedVariable
+        super(MRD, self).__init__()
         self._set_params(self._get_params())
 
     @property