Replace the throbber.gif sprite with two seperate gifs

Problem/Motivation

Throbber.gif is a sprite. This poses problems when one changes the padding of an autocomplete field, because the lower half, which is the spinning blue wheel, becomes visible.
In fact, even in Drupal core many autocomplete fields are so high, the lower half is visible.
http://screencast.com/t/GoypfycoPf

Having replaced the sprite with two seperate gifs numerous times in projects, I come to believe it is a really bad use-case for a sprite.

Proposed resolution

Replace the gif with a gif and a png, preferrable another file format for the gif if there is any (I guess there is none and we still have to use gifs for animated things). Center each gif for active/not active state and this uglyness is gone.
Attached you find the two seperate gifs, even if not yet a patch. This will come.

It may be the problem gets a more thorough solution https://drupal.org/node/675446 but you never know if an issue will land. It does not hurt to provide a simple solution until then.

There is a similar issue over here that proposes increasing the sprites height: https://drupal.org/node/1153366
Maybe one could see mine as a duplicate, maybe not. If so, feel free to mark it as duplicate.