What kind of menu did you use? Motion menu or Photoshop still?
If those images are not showing up in the assets area, the links might be broken to them or the images may have been erased? Can't really tell from what you are saying.
One suggestion - when you are writing a post to others who are not seeing what you are, think about what you are saying so that they will visually understand what you are describing. Details- are important.