Corrected code in writeframesraw():

            self._datawritten = self._datawritten + len(data) *
self._sampwidth
        else:
            self._file.write(data)
            self._datawritten = self._datawritten + len(data) *
self._sampwidth


Note that the default (not byte swapped) assignment to _datawritten must
also be multiplied by _sampwidth. If not, audio programs will ignore the
second half of a 16-bit-sample file.

As a side note, the calls to _patchheader() do not need to be protected
by this "if" statement:

        if self._datalength != self._datawritten:

_patchheader does the same test to optimize its operation.