StringIO in the cStringIO module in Python 2.7.2 doesn’t handle unicode strings properly. This bug has bitten me on a couple of occasions, in the recent past.

Just making a note for myself:

1. Use StringIO if speed doesn’t matter so much.
2. Whenever possible, just convert the input to StringIO to a string, if what you are doing doesn’t really require unicode strings.

Or may be it’s just time to move up to Python 2.7.3