I stumbled on this issue after getting some unexpected HTML output:

$ python
Python 2.4.2 (#2, Nov  5 2005, 12:26:27)
[GCC 3.3 20030304 (Apple Computer, Inc. build 1495)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
 >>> from qpy import h8
 >>> s = h8('an h8 string')
 >>> t = (1,2,3)
 >>> t += s
 >>> t
u'(1, 2, 3)an h8 string'
 >>>

I.e. I was inadvertently concatenating an h8 string to a tuple, and not
getting any complaints for it, as I would have expected... a bug?

mario