Not sure if it matters now, but before you fixed it in Stefan's profile, i was seeing that character more like a comma ",". Although it wasn't a comma. Too bad i did not take a screenshot at that time.
And from what i see in one of our MO discussion, this issue might have been introduced during migration to JForum where some of the characters weren't imported correctly. And looks like it's covered in this http://faq.javaranch.com/java/JForumTransition "Accented characters in display name and signature" which asks the users to fix it themselves (or we do it for them)