Python annoyance

Given the following code:

def index():
        try:
                import MySQLdb
        except:
                return "Couldn't import MySQL module"
        return "Yay Workyness"

inside a mod_python instance, is there any reason why it should return “Yay Workyness” and “Couldn’t import MySQL module” in roughly equal amounts? (MySQLdb in this case is a sub directory of the current working directory). Bugs I can cope with, but this inconsistancy is driving me insane…