I am not sure which terms to search for this with, perhaps you can help. Sometimes when I move around my emacs window, some grey clutter emerges on the left hand side. The file that I am working on is growing in size (82 Kb), but is not that huge (I would expect). I also have gradually added a bunch of things to the .emacs startup, but again, not that much. The computer is not overloaded with other apps either. I'm working with Windows 7.
The clutter is purely visual and apart from hiding the some letters briefly does not obstruct the use in any way. The clutter is easy to get rid of with some scrolling or looping through buffers, which works sometimes. Writing on the clutter also forces the cluttered part to be updated with the proper contents.
Any idea which problems I may be facing? And could it increase with file size? It looks like this:
The image of how it looks like does not seem to work with google drive, but it should be visible here: https://drive.google.com/file/d/0B-vbd3c7HrSJS240aUMxaV9xZmc/view?usp=sharing
Update
The problem persists when starting up with emacs -Q
(noinit), and with no open files.