I think it’s not an implicit vs. explicit call problem, rather repr vs. str.

IIRC, in 2.x it is allowed that __str__ returns a unicode object, and str will convert it to a str.  To do that, it will use the default encoding, which is ASCII in 2.5+, so your example cannot work.

Ideas for work-arounds:
- write a displayhook (http://docs.python.org/dev/library/sys#sys.displayhook) that converts unicode objects using sys.stout.encoding
- for 2.6+, test if setting PYTHONIOENCODING changes soemthing