can't get course in order

Hi heroes. I am having trouble with a course that was previously made by someone else, and my task is to finish it and publish it. the course is linear, with around 30 questions dispersed throughout the course. When I do a preview, and get to the slide before question 7, then hit next, it goes to the proper slide, but instead of being the next slide on the menu, it jumps to near the end of the course, and I see on the menu that there is about 15-20 questions all in a row. If I actually do the course, it appears that it will still go in order, i.e. it will do the three questions in a row then it will jump back to the proper order in the menu then continue on like nothing has happened. In story view, it looks completely linear, so i don't know how it happens that when I preview the project, a bunch of the questions get moved to the bottom of the menu. I hope this makes sense. If i can get this straightened out, i can go ahead and publish.