Assert error in debug when destructing

I'm building using the static version (11.1) of the skin library and control library.  Our application is somewhat complex manually getting controls from our control library in a separate DLL.  The main application is a dialog based app, this is where I load up the skin.  The application is metadata driven and the controls are dynamically drawn on the dialog, getting the controls (MFC or XTP) from this separate DLL.  It's bombing on this code:

CXTThemeManager::~CXTThemeManager()
{
    POSITION pos = m_mapDefaultFactories.GetStartPosition();
    void* pThemeFactoryClass;
    CXTThemeManagerStyleFactory* pFactory = 0;
    while (pos)
    {
        m_mapDefaultFactories.GetNextAssoc(pos, pThemeFactoryClass, (void *&)pFactory);
        SAFE_DELETE(pFactory);
    }

    ASSERT(m_factoryList.m_pHead == 0); // right here...
    m_factoryList.RemoveAll();
}


Any help would be appreciated.

Dave

Thank you.  I'll check it out.