python3.2 difficulty to use pre-generated pandas/msgpack.cpp
on all aged Debian/Ubuntus (e.g. wheeze) where I build using pre-cythonized sources python3.2 seems to become blind and tries only to look for msgpack.c, not msgpack.cpp:

```
~/pandas-0.13.0# python3.2 setup.py build_ext
running build_ext
Traceback (most recent call last):
  File "setup.py", line 583, in <module>
    **setuptools_kwargs)
  File "/usr/lib/python3.2/distutils/core.py", line 148, in setup
    dist.run_commands()
  File "/usr/lib/python3.2/distutils/dist.py", line 917, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python3.2/distutils/dist.py", line 936, in run_command
    cmd_obj.run()
  File "/usr/lib/python3.2/distutils/command/build_ext.py", line 344, in run
    self.build_extensions()
  File "setup.py", line 346, in build_extensions
    self.check_cython_extensions(self.extensions)
  File "setup.py", line 343, in check_cython_extensions
    """ % src)
Exception: Cython-generated file 'pandas/msgpack.c' not found.
                Cython is required to compile pandas from a development branch.
                Please install Cython or download a release package of pandas.

~/pandas-0.13.0# ls -l pandas/msgpack.cpp 
-rw-r--r-- 1 pbuilder pbuilder 570047 Jan  3 03:44 pandas/msgpack.cpp
```

I wonder if anyone ran into this misbehavior (before I start patching left and right ;-) )
