python-dateutil downgrade on 2.7.2
```
pip install pandas
```

downgrades my python-dateutil from 2.1 to 1.5. I'm on python 2.7.2, OSX 10.8, distribute==0.6.28, numpy==1.6.2. 

Is there any reason to believe that manually upgrading python-dateutil after installing pandas==0.8.1 will break pandas? How could I test the just-installed pandas? 
