Spinning blue circle for autocomplete field

I noticed this issue as well.

I'm pretty new to Drupal but it seems the problem is the default Drupal ajax throbber uses a single animated gif that gets shifted around instead of loading two different images. This works when the input form is limited in height, but the extra large ones in the corporate clean theme show the whole gif.
I tried upscaling the image 2X in the style sheet and it fit better but looked terrible so instead of found a 24x24px animated loading icon and copied it to corporateclean/images/spinner.gif.
I then added this to the end of corporateclean/style.css

html.js input.form-autocomplete {
background-position: 100% 6px;
background-size: 24px 24px;
background-image:none;
}

html.js input.throbbing{
background-image:url("./images/spinner.gif");
}

I'm satisfied with the results this gave me but if you want to kill the spinner completely don't add the image or the second paragraph of css.
I think this issue is probably an oversight on the theme developers part and I image it will get fixed eventually.
Also I'm not positive that I did this the "right" way as I'm new to Drupal but I know that it works for now.

I made a new gif of throbber and put it in sites/default/files/images

And then inserted this CSS

/*THROBBER*/
html.js input.form-autocomplete {
background-image: url(../../files/images/throbber.gif);
background-position-y: 8px;
}
html.js input.throbbing {
background-position-y: -18px;
}

I hope that this worked for you too :)

For what it's worth, I'm having this same issue with a few different themes. I'm wondering if there is another solution to this aside from having to alter the css for all the different themes. Heck it's even doing this with the default "Bartik" theme that comes out of the box with Drupal.

I didn't find much when trying to google the topic, but if anyone has some input/ideas please share. If I find information I'll come back and post it as well.

Oh, it might be worth noting, I installed the "Chosen" module and then within my view I changed the settings for "Selection Type" on my exposed filter to "Dropdown" instead of "Autocomplete" Since I have the chosen module enabled the regular dropdown option still works like the autocomplete option, actually it's much nicer because you aren't forced to enter a comma when you want to add multiple terms and it makes removing multi terms easier as well.

https://drupal.org/project/chosen

This is a known issue and it's already fixed in 8.x, but still need to be backported to 7.x
https://drupal.org/node/1069152
In the above issue there is a patch you can apply manually or via drush make.