[meta] Why is the search button (magnifier) turning into two X's on mouse over?

edit

The CSS is wrong. Line 690 of style.css should be

  background: -146px -37px url(../images/sprites.png) no-repeat !important;

(I added the !important statement. Btw. I really don't know why there are six background-image: none; rules there.)

The positioning for the background image is overriden by rule on line 765 and its !imporant definition of background-position for hover input buttons.

button:hover,
input[type="submit"]:hover,
.button:hover,
.btn:hover {
  background-position: 0 0 !important;