I zoomed in and then out of a picture and was left with blue lines crossing horizontally over it.

Sounds like you did not understand the procedure for the exam you wanted. First, clicking on the exam type (Posture Number), or the anatomical area, requires a single click. Starting with a double click places the first point of the exam at the spot of the second click and will cause lines across the screen. Please review the video for the exam you want to do from our video help library at www.posturepro.com