I've read this thread...
...but I didn't want to hijack it so I started a new thread.
I've noticed the cursor jumping to the end too and I can recreate this on the default editor...
in IE 11 or Chrome 43.0.2357.134 m, but not in Firefox 39.0
Note: It would be so much easier if you allowed .txt files to be attached (just pictures?? draconian)
Download the source text if you need it and open in Notepad and copy from there: https://drive.google.com/file/d/0By6eYrB-wqpFc0dWa3hWTWRBbWs/view?usp=sharing