I'm afraid this is dirty too, but I'll be (pleasantly) surprised if there's a clean fix to this.
Put all your <li>
s on one line:
<li class="nav"><a class="nav" href="#">One1</a></li><li class="nav"><a class="nav" href="#">Two</a></li><li class="nav"><a class="nav" href="#">Three</a></li><li class="nav"><a class="nav" href="#">Four</a></li>
Sorry.