diff --git a/GPy/core/parameterization/index_operations.py b/GPy/core/parameterization/index_operations.py
index 091b6372..b816e05f 100644
--- a/GPy/core/parameterization/index_operations.py
+++ b/GPy/core/parameterization/index_operations.py
@@ -57,6 +57,7 @@ class ParameterIndexOperations(object):
     You can give an offset to set an offset for the given indices in the
     index array, for multi-param handling.
     '''
+    _offset = 0
     def __init__(self, constraints=None):
         self._properties = IntArrayDict()
         if constraints is not None:
@@ -120,6 +121,14 @@ class ParameterIndexOperations(object):
             return removed.astype(int)
         return numpy.array([]).astype(int)
     
+    def update(self, parameter_index_view, offset=0):
+        for i, v in parameter_index_view.iteritems():
+            self.add(i, v+offset)
+
+    
+    def copy(self):
+        return ParameterIndexOperations(dict(self.iteritems()))
+    
     def __getitem__(self, prop):
         return self._properties[prop]
     
@@ -223,9 +232,9 @@ class ParameterIndexOperationsView(object):
         import pprint
         return pprint.pformat(dict(self.iteritems()))
 
-    def update(self, parameter_index_view):
+    def update(self, parameter_index_view, offset=0):
         for i, v in parameter_index_view.iteritems():
-            self.add(i, v)
+            self.add(i, v+offset)
     
     
     def copy(self):
diff --git a/GPy/core/parameterization/parameter_core.py b/GPy/core/parameterization/parameter_core.py
index cfee60bd..65504652 100644
--- a/GPy/core/parameterization/parameter_core.py
+++ b/GPy/core/parameterization/parameter_core.py
@@ -72,6 +72,13 @@ class Parentable(object):
     def has_parent(self):
         return self._direct_parent_ is not None
 
+    def _notify_parent_change(self):
+        for p in self._parameters_:
+            p._parent_changed(self)
+
+    def _parent_changed(self):
+        raise NotImplementedError, "shouldnt happen, Parentable objects need to be able to change their parent"
+
     @property
     def _highest_parent_(self):
         if self._direct_parent_ is None:
@@ -182,11 +189,9 @@ class Constrainable(Nameable, Indexable, Parameterizable):
     # Constrain operations -> done
     #===========================================================================
     def _parent_changed(self, parent):
-        c = self.constraints
         from index_operations import ParameterIndexOperationsView
         self.constraints = ParameterIndexOperationsView(parent.constraints, parent._offset_for(self), self.size)
-        self.constraints.update(c)
-        del c
+        self._fixes_ = None
         for p in self._parameters_:
             p._parent_changed(parent)
 
diff --git a/GPy/core/parameterization/parameterized.py b/GPy/core/parameterization/parameterized.py
index 80bf2959..a976eb93 100644
--- a/GPy/core/parameterization/parameterized.py
+++ b/GPy/core/parameterization/parameterized.py
@@ -87,17 +87,20 @@ class Parameterized(Constrainable, Pickleable, Observable, Gradcheckable):
         elif param not in self._parameters_:
             # make sure the size is set
             if index is None:
+                self.constraints.update(param.constraints, self.size)
                 self._parameters_.append(param)
             else:
                 start = sum(p.size for p in self._parameters_[:index])
                 self.constraints.shift(start, param.size)
+                self.constraints.update(param.constraints, start)
                 self._parameters_.insert(index, param)
             self.size += param.size
         else:
             raise RuntimeError, """Parameter exists already added and no copy made"""
         self._connect_parameters()
-        for p in self._parameters_:
-            p._parent_changed(self)
+        self._notify_parent_change()
+        self._connect_fixes()
+
 
     def add_parameters(self, *parameters):
         """
@@ -120,7 +123,13 @@ class Parameterized(Constrainable, Pickleable, Observable, Gradcheckable):
         param._direct_parent_ = None
         param._parent_index_ = None
         param._connect_fixes()
+        param._notify_parent_change()
+        pname = adjust_name_for_printing(param.name)
+        if pname in self._added_names_:
+            del self.__dict__[pname]
         self._connect_parameters()
+        #self._notify_parent_change()
+        self._connect_fixes()
 
     def _connect_parameters(self):
         # connect parameterlist to this parameterized object
@@ -149,7 +158,6 @@ class Parameterized(Constrainable, Pickleable, Observable, Gradcheckable):
             elif not (pname in not_unique):
                 self.__dict__[pname] = p
                 self._added_names_.add(pname)
-        self._connect_fixes()
 
     #===========================================================================
     # Pickling operations
diff --git a/GPy/testing/parameterized_tests.py b/GPy/testing/parameterized_tests.py
new file mode 100644
index 00000000..ff57606a
--- /dev/null
+++ b/GPy/testing/parameterized_tests.py
@@ -0,0 +1,93 @@
+'''
+Created on Feb 13, 2014
+
+@author: maxzwiessele
+'''
+import unittest
+import GPy
+import numpy as np
+
+class Test(unittest.TestCase):
+
+    def setUp(self):
+        self.rbf = GPy.kern.rbf(1)
+        self.white = GPy.kern.white(1)
+        from GPy.core.parameterization import Param
+        from GPy.core.parameterization.transformations import Logistic
+        self.param = Param('param', np.random.rand(25,2), Logistic(0, 1))
+        
+        self.test1 = GPy.core.Parameterized("test model")
+        self.test1.add_parameter(self.white)
+        self.test1.add_parameter(self.rbf, 0)
+        self.test1.add_parameter(self.param)
+        
+    def test_add_parameter(self):
+        self.assertEquals(self.rbf._parent_index_, 0)
+        self.assertEquals(self.white._parent_index_, 1)
+        pass
+    
+    def test_fixes(self):
+        self.white.fix(warning=False)
+        self.test1.remove_parameter(self.test1.param)
+        self.assertTrue(self.test1._has_fixes())
+
+        from GPy.core.parameterization.transformations import FIXED, UNFIXED
+        self.assertListEqual(self.test1._fixes_.tolist(),[UNFIXED,UNFIXED,FIXED])
+
+        self.test1.add_parameter(self.white, 0)
+        self.assertListEqual(self.test1._fixes_.tolist(),[FIXED,UNFIXED,UNFIXED])
+        
+        
+    def test_remove_parameter(self):
+        from GPy.core.parameterization.transformations import FIXED, UNFIXED, __fixed__
+        self.white.fix()
+        self.test1.remove_parameter(self.white)
+        self.assertIs(self.test1._fixes_,None)
+        
+        self.assertListEqual(self.white._fixes_.tolist(), [FIXED])
+        self.assertIs(self.white.constraints,self.white.white.constraints._param_index_ops)
+        self.assertEquals(self.white.white.constraints._offset, 0)
+        self.assertIs(self.test1.constraints, self.rbf.constraints._param_index_ops)
+        self.assertIs(self.test1.constraints, self.param.constraints._param_index_ops)        
+        
+        self.test1.add_parameter(self.white, 0)
+        self.assertIs(self.test1.constraints, self.white.constraints._param_index_ops)
+        self.assertIs(self.test1.constraints, self.rbf.constraints._param_index_ops)
+        self.assertIs(self.test1.constraints, self.param.constraints._param_index_ops)        
+        self.assertListEqual(self.test1.constraints[__fixed__].tolist(), [0])
+        self.assertIs(self.white._fixes_,None)
+        self.assertListEqual(self.test1._fixes_.tolist(),[FIXED] + [UNFIXED] * 52)
+        self.test1.remove_parameter(self.white)
+        self.assertIs(self.test1._fixes_,None)
+        self.assertListEqual(self.white._fixes_.tolist(), [FIXED])
+        self.assertIs(self.white.constraints,self.white.white.constraints._param_index_ops)
+        self.assertIs(self.test1.constraints, self.rbf.constraints._param_index_ops)
+        self.assertIs(self.test1.constraints, self.param.constraints._param_index_ops)        
+        
+    def test_add_parameter_already_in_hirarchy(self):
+        self.test1.add_parameter(self.white._parameters_[0])
+        
+    def test_default_constraints(self):
+        self.assertIs(self.rbf.rbf.variance.constraints._param_index_ops, self.rbf.constraints._param_index_ops)
+        self.assertIs(self.test1.constraints, self.rbf.constraints._param_index_ops)
+        self.assertListEqual(self.rbf.constraints.indices()[0].tolist(), range(2))
+        from GPy.core.parameterization.transformations import Logexp
+        kern = self.rbf+self.white
+        self.assertListEqual(kern.constraints[Logexp()].tolist(), range(3))
+
+    def test_constraints(self):
+        self.rbf.constrain(GPy.transformations.Square(), False)
+        self.assertListEqual(self.test1.constraints[GPy.transformations.Square()].tolist(), range(2))
+        self.assertListEqual(self.test1.constraints[GPy.transformations.Logexp()].tolist(), [2])
+        
+        self.test1.remove_parameter(self.rbf)
+        self.assertListEqual(self.test1.constraints[GPy.transformations.Square()].tolist(), [])
+
+    def test_constraints_views(self):
+        self.assertEqual(self.white.constraints._offset, 2)
+        self.assertEqual(self.rbf.constraints._offset, 0)
+        self.assertEqual(self.param.constraints._offset, 3)
+
+if __name__ == "__main__":
+    #import sys;sys.argv = ['', 'Test.test_add_parameter']
+    unittest.main()
\ No newline at end of file