Modify getTitle in craft/app/widgets/QuickPostWidget.php to display the section title in lower case to match the widget title text.

QuickPostWidget.php

public function getTitle()
	{
		if (craft()->hasPackage(CraftPackage::PublishPro))
		{
			$section = $this->_getSection();

			if ($section)
			{
				return Craft::t('Post a new {section} entry', array('section' => strtolower($section->name)));
			}
		}

		return $this->getName();
	}