datetime64 is incorrectly converted by series.values
Using pandas 0.11.
Calling series.values on a datetime64 series will mess up the values, truncating them to 1970.

import pandas as pd
y = pd.DataFrame(pd.date_range('12/15/2012', '1/6/2013', freq='B'), columns=['dt'])
# Look at y, note the dates are all in 2012 and 2013. So far so good.

z = y.values
# Look at z -- uh oh, all the values are now in 1970.
