Steps to reproduce:
1)In an editor for a perl file right click the tab for the editor and select "new editor"
2)Goto a different line in the file in one of the editors
3)Make a change and save
Work around:
1)Make a copy of the file you wish to edit and use this file for "read only" views(editor instances) into the file
Works on Mars.SR2 / EPIC 0.7.0.