Game Engine: Joyeux Noel -> Joyeux Noël

Hello.

I do not know how to solve an accent problem with texts in Blender Game Engine:

If I set a text property to Joyeux Noël in the logic Editor panel, the game displays it correctly.
But if I set this property in an external script, the display is Joyeux NoA°A°l

I suppose I have to tell python what encoding is used (UTF8- ascii or something else)
Probably this problem has been solved by a non english person on this forum.

I do not know if Blender 2.5 keyboard will be internationalized or not.

Fortunately, I can write it here correctly on this forum:
Joyeux Noël à tous.

To be more accurate, all accents are displayed correctly in the game engine if written in the logic editor, and displayed wrongly if written in external scripts.
é è ç à ü Û, … etc, meaning my bitmap font is OK.
(I did use the blendFont.py script under blender 2.49, and modified it to get all french letters in one bitmap file.)