np.max(Index) creates an invalid index.
Pandas version: '0.12.0'
Numpy version: '1.6.1'

How to reproduce:
ser = pd.Series([2, 4, 6], index=[0, 2, 3])
ids = ser.index
x = np.max(ids)

Now, two things happen:
*) type(x) is Index
*) x is a 0-d array (so getting x[0]) crashes
*) print x crashes as well:

/home/olexiy/clients/olexiy-validators/google3/blaze-bin/quality/ranklab/main/tools/iranklab.runfiles/google3/third_party/py/pandas/core/common.py in pprint_thing(thing, _nest_lvl, escape_chars, default_escapes, quote_strings)
   2065         result = fmt % as_escaped_unicode(thing)
   2066     else:
-> 2067         result = as_escaped_unicode(thing)
   2068 
   2069     return unicode(result)  # always unicode

/home/olexiy/clients/olexiy-validators/google3/blaze-bin/quality/ranklab/main/tools/iranklab.runfiles/google3/third_party/py/pandas/core/common.py in as_escaped_unicode(thing, escape_chars)
   2026 
   2027         try:
-> 2028             result = unicode(thing)  # we should try this first
   2029         except UnicodeDecodeError:
   2030             # either utf-8 or we replace errors

RuntimeError: maximum recursion depth exceeded while calling a Python object
