Perhaps you haven't considered this option yet, but it appears that your divs are already structured like a table. How about giving this approach a try:
<table class="cmenu">
<tr class="cbtn add">
<td class="cbtnSymbol">+</td>
<td class="cbtnLabel">Add</td>
</tr>
<tr class="cbtn add">
<td class="cbtnSymbol">-</td>
<td class="cbtnLabel">Delete</td>
</tr>
</table>
This method could streamline your CSS and make things simpler. For instance, you may not require the use of display: inline-block anymore.
DEMO http://jsfiddle.net/DwGEa/37/