```
________________ sympy/matrices/tests/test_matrices.py:test_exp ________________
  File "/home/franzb87/workspace/sympy-eclipse/sympy/sympy/matrices/tests/test_matrices.py", line 1456, in test_exp
    assert exp(m) == m_exp
  File "sympy/core/cache.py", line 92, in wrapper
    func_cache_it_cache[k] = r = func(*args, **kw_args)
  File "sympy/core/function.py", line 280, in __new__
    result = super(Function, cls).__new__(cls, *args, **options)
  File "sympy/core/cache.py", line 92, in wrapper
    func_cache_it_cache[k] = r = func(*args, **kw_args)
  File "sympy/core/function.py", line 126, in __new__
    evaluated = cls.eval(*args)
  File "sympy/functions/elementary/exponential.py", line 285, in eval
    return arg.exp()
  File "sympy/matrices/matrices.py", line 1867, in exp
    U, D = self.diagonalize()
  File "sympy/matrices/matrices.py", line 3238, in diagonalize
    P = P.col_insert(P.cols, vec)
  File "sympy/matrices/matrices.py", line 3641, in col_insert
    return mti.row_join(self)
  File "sympy/matrices/matrices.py", line 3542, in row_join
    newmat[:, :self.cols] = self
  File "sympy/matrices/immutable.py", line 62, in __setitem__
    raise TypeError("Cannot set values of ImmutableMatrix")
TypeError: Cannot set values of ImmutableMatrix
```

This is what I get without `Matrix( )`