plot of Series fails
The example here fails with 0.8.1 (worked with 0.8.0)
http://pandas.pydata.org/pandas-docs/dev/computation.html?highlight=outlier#moving-rolling-statistics-moments

In [1]: from pandas import *

In [2]: from numpy.random import randn

In [3]: ts = Series(randn(1000), index=date_range('1/1/2000', periods=1000))

In [4]: ts = ts.cumsum()

In [5]: ts.plot(style='k--')
/usr/lib64/python2.6/site-packages/matplotlib/backends/backend_gtk.py:621: DeprecationWarning: Use the new widget gtk.Tooltip
##   self.tooltips = gtk.Tooltips()

AttributeError                            Traceback (most recent call last)

/home/jgarcke/code/python_fx_tools/<ipython console> in <module>()

/home/jgarcke/Prog/lib64/python2.6/site-packages/pandas-0.8.1-py2.6-linux-x86_64.egg/pandas/tools/plotting.pyc in plot_series(series, label, kind, use_index, rot, xticks, yticks, xlim, ylim, ax, style, grid, logy, secondary_y, *_kwds)
   1292                      secondary_y=secondary_y, *_kwds)
   1293 
-> 1294     plot_obj.generate()
   1295     plot_obj.draw()
   1296 

/home/jgarcke/Prog/lib64/python2.6/site-packages/pandas-0.8.1-py2.6-linux-x86_64.egg/pandas/tools/plotting.pyc in generate(self)
    573         self._compute_plot_data()
    574         self._setup_subplots()
--> 575         self._make_plot()
    576         self._post_plot_logic()
    577         self._adorn_subplots()

/home/jgarcke/Prog/lib64/python2.6/site-packages/pandas-0.8.1-py2.6-linux-x86_64.egg/pandas/tools/plotting.pyc in _make_plot(self)
    858         if self.use_index and self._use_dynamic_x():
    859             data = self._maybe_convert_index(self.data)
--> 860             self._make_ts_plot(data, **self.kwds)
    861         else:
    862             import matplotlib.pyplot as plt

/home/jgarcke/Prog/lib64/python2.6/site-packages/pandas-0.8.1-py2.6-linux-x86_64.egg/pandas/tools/plotting.pyc in _make_ts_plot(self, data, *_kwargs)
    918 
    919             newlines = tsplot(data, plotf, ax=ax, label=label, style=self.style,
--> 920                              *_kwargs)
    921             ax.grid(self.grid)
    922             lines.append(newlines[0])

/home/jgarcke/Prog/lib64/python2.6/site-packages/pandas-0.8.1-py2.6-linux-x86_64.egg/pandas/tseries/plotting.pyc in tsplot(series, plotf, **kwargs)
     80     # set date formatter, locators and rescale limits

```
 81     format_dateaxis(ax, ax.freq)
```

---> 82     left, right = _get_xlim(ax.get_lines())
     83     ax.set_xlim(left, right)
     84 

/home/jgarcke/Prog/lib64/python2.6/site-packages/pandas-0.8.1-py2.6-linux-x86_64.egg/pandas/tseries/plotting.pyc in _get_xlim(lines)
    210     for l in lines:
    211         x = l.get_xdata()
--> 212         left = min(x[0].ordinal, left)
    213         right = max(x[-1].ordinal, right)
    214     return left, right

AttributeError: 'numpy.int64' object has no attribute 'ordinal'
