ERR: Poor error message passing iterator to DataFrame constructor.
E.g.:

``` python
from itertools import izip
df = DataFrame(izip(range(3), range(-3, 1), list('abc')), columns=list('abc'))
---------------------------------------------------------------------------
PandasError                               Traceback (most recent call last)
<ipython-input-3-15234514160e> in <module>()
      1 from itertools import izip
      2
----> 3 df = DataFrame(izip(range(3), range(-3, 1), list('abc')), columns=list('abc'))

../pandas/core/frame.pyc in __init__(self, data, index, columns, dtype, copy)
    270                                          copy=False)
    271             else:
--> 272                 raise PandasError('DataFrame constructor not properly called!')
    273
    274         NDFrame.__init__(self, mgr, fastpath=True)

PandasError: DataFrame constructor not properly called!
```
