Memory leak on mundane string retrieval?

[GHS]

Hi all.  I'm testing my iPhone app for leaks with Instruments, and it's flagging the following routine as being a source of malloc leaks in conjunction with std::string.  I can't see any leaks here, since I'm doing everything by reference.  Am I missing something?  Thanks!

std::string DeXMLator::getChildElementAsString(const TiXmlElement* pParentElement, const std::string& childName)
{
    const TiXmlElement* pCurrElement = dynamic_cast<const TiXmlElement*>(pParentElement->FirstChild(childName.c_str()));
    if(pCurrElement)
    {
        if(pCurrElement->GetText())
        {
            return pCurrElement->GetText();
        }
    }
    return "";
}