If the text-indent is negative the hover area for the element is moved outside the element. Last good nightly: 2012-06-30 First bad nightly: 2012-07-01 http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=f08d285b63b0&tochange=d9d61d199b11 STR 1: 1. Open the url 2. Try clicking the search field Actual results: The search button is clicked Expected results: The search field should be focused STR 2: 1. Open the testcase 2. Hover the first or second button Actual results: The last button is marked red Expected results: The button hovered should be red