Text area jumpy

I am using the latest version. In an long file was editing using the text window/area to update a select bibliography I have at my site. Every time I hit delete or the backspace key, the window and text jumped. Is this just happening for me? I kept losing my place and had to find my way back to the sentence I was editing. Could it be because the page is pretty long.

Anyway, I just wanted to post this to see if anyone has a similar problem.