If you use the menu template below you can target the the last item with li.last a in css to increase it just enough to cover that last bit...
{if $count > 0}
<div id="menuwrapper">
<ul id="primary-nav">
{* begin calguy *}
{foreach from=$nodelist item=node name='menu'}
{assign var='last' value=''}
{if $smarty.foreach.menu.last}
{assign var='last' value='last '}
{/if}
{* end calguy *}
{if $node->depth > $node->prevdepth}
{repeat string="<ul>" times=$node->depth-$node->prevdepth}
{elseif $node->depth < $node->prevdepth}
{repeat string="</li></ul>" times=$node->prevdepth-$node->depth}
</li>
{elseif $node->index > 0}</li>
{/if}
{if $node->parent == true or ($node->current == true and $node->haschildren == true)}
<li class="{$last}menuactive menuparent"><a class="menuactive menuparent"
{elseif $node->current == true}
<li class="{$last}menuactive"><a class="menuactive"
{elseif $node->haschildren == true}
<li class="{$last}menuparent"><a class="menuparent"
{elseif $node->type == 'sectionheader'}
<li class="{$last}sectionheader"><span> {$node->menutext} </span>
{elseif $node->type == 'separator'}
<li style="list-style-type: none;"> <hr class="separator" />
{elseif empty($last)}
{* not the last menu item, but not a separator, header, parent, or active either *}
<li><a
{else}
{* last menu item *}
<li class="{$last}"><a
{/if}
{if $node->type != 'sectionheader' and $node->type != 'separator'}
href="{$node->url}" {if $node->accesskey != ''}accesskey="{$node->accesskey}" {/if}{if $node->tabindex != ''}tabindex="{$node->tabindex}" {/if}{if $node->titleattribute != ''}title="{$node->titleattribute}"{/if}{if $node->target ne ""} target="{$node->target}"{/if}><dfn>{$node->hierarchy}: </dfn>{$node->menutext}</a>
{elseif $node->type == 'sectionheader'}
><dfn>{$node->hierarchy}: </dfn>{$node->menutext}</a>
{/if}
{/foreach}
{repeat string="</li></ul>" times=$node->depth-1} </li>
</ul>
<div class="clearb"></div>
</div>
{/if}
