The problem we've faced is somehow related with images in Moodle quiz questions.
The images we've put to multiple-choice questions in quizes are sometimes shown and sometimes they are not.
Several teachers while editing their multiple-choice questions were putting images either directly in the text editor, either in the "image to display" section.
But probably that is not the case, because unshown images were reported in both situations.
The strange thing is - if to log on as a teacher, or administrator, you can see image in question preview, but if you log on as a student the image is not shown on the same question.
So we can't find any dependency or the reason for that.
Any suggestions?