I just checked in pydoc.py 1.58. The change of type("").__name__ from "string" to "str" between Python 2.1 and 2.2 busted the special method lookup in pydoc.HTMLRepr and pydoc.TextRepr. This belongs in 2.2.1.
SF seems at least mildly busted at the moment. I wasn't able to search for bugs containing "pydoc". I didn't bother filing a bug report.