.input-{pre,ap}pend select requires two clicks to activate dropdown in FF

Created by: eternicode

In Firefox 11, addon'd selects require two clicks to open the dropdown. I've tracked the issue down to these selects having position:relative set on them on focus:

// INPUT GROUPS
// ------------

// Allow us to put symbols and text within the input field for a cleaner look
.input-prepend,
.input-append {
  [snip]
  input,
  select,
  .uneditable-input {
    [snip]
    // Make input on top when focused so blue border and shadow always show
    &:focus {
      position: relative;
      z-index: 2;
    }
  }
  [snip]
}

Broken: http://jsfiddle.net/WBaA2/ Working: http://jsfiddle.net/WBaA2/1/