DataFrame.to_hdf append feature does behave properly
I create a DataFrame and save it to disk as an hdf5 file, as follows:
df.to_hdf(fname, 'table')
This behaves as expected. But when I try to append to the existing hdf5 file, 
df.to_hdf(fname, 'table',append=True)
pandas returns an error:
ValueError: Can only append to Tables
