Editing YouTube or Disqus comments, Safari window scrolls up

Hi,

I have an annoying problem, that's been going on for over two years. When I edit one of my comments in YouTube or Disqus, ie. highlighting text in edit mode, the Safari window automatically scrolls up to the top of the page. Why is this happening? I've updated Safari several times, but the problem is never fixed.
Is this a common problem, if so, why isn't Apple fixing it already?

Thanks!

No one else has this issue?