Error in test suite for eval
This is on the VM running pandas windows builds.
Windows XP
Python 2.7 32-bit
numpy 1.7.1

```
======================================================================
FAIL: pandas.computation.tests.test_eval.TestAlignment.test_basic_series_frame_alignment('numexpr', 'python')
----------------------------------------------------------------------
Traceback (most recent call last):
  File "c:\python27\x32\lib\site-packages\nose\case.py", line 197, in runTest
    self.test(*self.arg)
  File "C:\workspace\pandas-windows-test-py27\pandas\computation\tests\test_eval.py", line 873, in check_basic_series_frame_alignment
    testit(r_idx_type, c_idx_type, index_name)
  File "C:\workspace\pandas-windows-test-py27\pandas\computation\tests\test_eval.py", line 868, in testit
    assert_frame_equal(res, expected)
  File "C:\workspace\pandas-windows-test-py27\pandas\util\testing.py", line 448, in assert_frame_equal
    assert_index_equal(left.columns, right.columns)
  File "C:\workspace\pandas-windows-test-py27\pandas\util\testing.py", line 394, in assert_index_equal
    right.dtype))
AssertionError: [index] left [object Index([0, 2, 2000-01-03 00:00:00, 2000-01-04 00:00:00, 2000-01-05 00:00:00, 2000-01-06 00:00:00, 2000-01-07 00:00:00, 1, 2000-01-10 00:00:00, 3, 2000-01-11 00:00:00, 4], dtype='object')], right [Index([2000-01-03 00:00:00, 2000-01-04 00:00:00, 2000-01-05 00:00:00, 2000-01-06 00:00:00, 2000-01-07 00:00:00, 2000-01-10 00:00:00, 2000-01-11 00:00:00, 0, 1, 2, 3, 4], dtype='object') object]
```
