I have been moderating Moodle for a few years now and have never encountered this problem.  I recently just created a new course and have Manually Enrolled users.  For some reason these users cannot see the course.  I have never had this problem in the past.  I've tried to unenroll and enroll over and over, still no luck.  

I usually copy a previous course and just update.  I have never had this issue.  I would greatly appreciate any advice since I have not messed with any settings.