New Excel changes cause an extra line to be generated in the Excel file
An example:

``` python

In [9]: data = pandas.ExcelFile("sample.xls") # generated with df.to_excel()

In [10]: data.parse(data.sheet_names[0], index_col=0)
Out[10]: 
         Value
ID         NaN
ID1  38.625700
ID2  44.691054

```

To be more clear, `ID` is the original index name, but it is shifted down one row when saving to Excel, and then it is picked up as a regular row by the Excel parser.

This kinds of complicates parsing if I'm expecting to read something generated by to_excel()...
