NumPy error

[jason]

Hello:

I am using the following versions of Python and packages on Windows XP 
(SP2):

Python 2.4.2
NumPy  0.9.4.win32-py2.4
SciPy 0.4.4 for Python 2.4 and Pentium 4/SSE2

In the Python Shell I am running the following:

>>> from scipy.optimize import fmin
>>> def rosen(x):
              return sum(100.0*(x[1:]-x[:-1]**2.0)**2.0 + (1-x[:-1])**2.0)

>>> x0 = [1.3, 0.7, 0.8, 1.9, 1.2]
>>> xopt = fmin(rosen, x0)

I get the following error:

Traceback (most recent call last):
  File "<pyshell#6>", line 1, in -toplevel-
    xopt = fmin(rosen, x0)
  File "C:\Python24\Lib\site-packages\scipy\optimize\optimize.py", line 191, 
in fmin
    sim = Num.zeros((N+1,N),x0.dtypechar)
AttributeError: 'numpy.ndarray' object has no attribute 'dtypechar'

Any idea what the problem might be?

Thanks.