Dataframe.from_dict inconsistent behavior
python 3.4, pandas version 0.16.2

this works:

```
    monthly = {'datetime_col_to_use':['START DATE'],
      'colnames': ["TYPE", "START DATE", "END DATE", "USAGE", "UNITS", "COST", "NOTES"],
      'header_size':4,
      'concat_datetime_cols': False}

    monthly_df = pd.DataFrame.from_dict(monthly, orient='index')
```

![screen shot 2015-09-30 at 5 32 06 pm](https://cloud.githubusercontent.com/assets/5185401/10210243/3ae55f3e-6799-11e5-9e12-fb8200a4c496.png)

but this doesn't:

```
    hourly = {'datetime_col_to_use': ['START TIME', 'DATE'],
     'colnames': ["TYPE", "DATE", "START TIME", "END TIME", "USAGE", "UNITS", "COST", "NOTES"],
     'header_size':4,
     'concat_datetime_cols': True}

    hourly_df = pd.DataFrame.from_dict(hourly, orient='index')
```

Full traceback:

```
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-18-66cef4447f7e> in <module>()
----> 1 hourly_df = pd.DataFrame.from_dict(hourly, orient='index')
      2 #hourly_df.columns=['hourly']
      3 #hourly_df.head()

/home/vagrant/venv/lib/python3.4/site-packages/pandas/core/frame.py in from_dict(cls, data, orient, dtype)
    681             raise ValueError('only recognize index or columns for orient')
    682 
--> 683         return cls(data, index=index, columns=columns, dtype=dtype)
    684 
    685     @deprecate_kwarg(old_arg_name='outtype', new_arg_name='orient')

/home/vagrant/venv/lib/python3.4/site-packages/pandas/core/frame.py in __init__(self, data, index, columns, dtype, copy)
    249             if len(data) > 0:
    250                 if is_list_like(data[0]) and getattr(data[0], 'ndim', 1) == 1:
--> 251                     arrays, columns = _to_arrays(data, columns, dtype=dtype)
    252                     columns = _ensure_index(columns)
    253 

/home/vagrant/venv/lib/python3.4/site-packages/pandas/core/frame.py in _to_arrays(data, columns, coerce_float, dtype)
   4917     if isinstance(data[0], (list, tuple)):
   4918         return _list_to_arrays(data, columns, coerce_float=coerce_float,
-> 4919                                dtype=dtype)
   4920     elif isinstance(data[0], collections.Mapping):
   4921         return _list_of_dict_to_arrays(data, columns,

/home/vagrant/venv/lib/python3.4/site-packages/pandas/core/frame.py in _list_to_arrays(data, columns, coerce_float, dtype)
   4998     else:
   4999         # list of lists
-> 5000         content = list(lib.to_object_array(data).T)
   5001     return _convert_object_array(content, columns, dtype=dtype,
   5002                                  coerce_float=coerce_float)

pandas/src/inference.pyx in pandas.lib.to_object_array (pandas/lib.c:58728)()

TypeError: object of type 'bool' has no len()
```
