Safari will display in the console:

```
[Error] RangeError: Maximum call stack size exceeded.
    updateOriginal (yui_combo.php:11734)
    (anonymous function) (yui_combo.php:13268)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:30549)
    _notify (yui_combo.php:31985)
    _proxy (yui_combo.php:31903)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:20467)
    focus
    m (first.js:41:1047)
    some
    i (first.js:41:386)
    addRange
    (anonymous function) (yui_combo.php:3281)
    (anonymous function) (yui_combo.php:3327)
    setSelection (yui_combo.php:13562)
    restoreSelection (yui_combo.php:13361)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:30549)
    _notify (yui_combo.php:31985)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:20467)
    addRange
    (anonymous function) (yui_combo.php:3281)
    (anonymous function) (yui_combo.php:3327)
    setSelection (yui_combo.php:13562)
    restoreSelection (yui_combo.php:13361)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:30549)
    _notify (yui_combo.php:31985)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:20467)
    addRange
    (anonymous function) (yui_combo.php:3281)
    (anonymous function) (yui_combo.php:3327)
    setSelection (yui_combo.php:13562)
    restoreSelection (yui_combo.php:13361)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:30549)
    _notify (yui_combo.php:31985)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
    _fire (yui_combo.php:13447)
    fire (yui_combo.php:13416)
    (anonymous function) (yui_combo.php:20467)
    addRange
    (anonymous function) (yui_combo.php:3281)
    (anonymous function) (yui_combo.php:3327)
    setSelection (yui_combo.php:13562)
    restoreSelection (yui_combo.php:13361)
    _notify (yui_combo.php:13680)
    notify (yui_combo.php:13709)
    _notify (yui_combo.php:13372)
    _procSubs (yui_combo.php:13498)
    fireSimple (yui_combo.php:13465)
```
With about 50 repeats and become un-responsive for 10-30 seconds.