It inserts the course number to give teachers and admins access to the files area for that specific course. That way you can use the htmlarea editor to select images you uploaded, etc... (and I may be wrong but I think that's why you don't see it logged in as a student on moodle.org)
Can't help you with your html editor problem, but I have similar problems with the html editor loading only half the time. Sofar none of the solutions have helped.