diff --git a/GPy/inference/optimization.py b/GPy/inference/optimization.py
index 2e29fe6a..0a72aa08 100644
--- a/GPy/inference/optimization.py
+++ b/GPy/inference/optimization.py
@@ -204,7 +204,7 @@ class opt_scg(Optimizer):
     def opt(self, f_fp = None, f = None, fp = None):
         assert not f is None
         assert not fp is None
-        opt_result = SCG (f,fp,self.x_init, display=self.messages,
+        opt_result = SCG (f,fp,self.x_init, display=self.messages)
 
 def get_optimizer(f_min):
     # import rasmussens_minimize as rasm
diff --git a/GPy/util/linalg.py b/GPy/util/linalg.py
index cf023284..f21502a5 100644
--- a/GPy/util/linalg.py
+++ b/GPy/util/linalg.py
@@ -18,8 +18,7 @@ def trace_dot(a,b):
     """
     efficiently compute the trace of the matrix product of a and b
     """
-    assert a.shape==b.T.shape
-    return np.dot(a.flatten(),b.T.flatten())
+    return np.sum(a*b)
 
 def mdot(*args):
    """Multiply all the arguments using matrix product rules.