Bug 136241 [regression]Preview template in web viewer and pdf didn't get correct effect.
Description: Preview template items in web viewer and pdf didn't get correct effect. Steps to reproduce: 1. Create template items. 2. Preview in Web Viewer and pdf. Expected result: Same effect as in html. Actual result: In web viewer, see only blank box. In pdf, blank page.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
*            the module information needed for the check, and records any
	 *            errors
	 * @param prop
	 *            the property whose type is element reference
	 * @return the element reference value is always returned, which contains
	 *         the information of element resolution.
	 */
	public ElementRefValue resolveElementReference( Module module,
			ElementPropertyDefn prop )
	{
		Object value = propValues.get( prop.getName( ) );
		assert value == null || value instanceof ElementRefValue;
		assert prop.getTypeCode( ) == PropertyType.ELEMENT_REF_TYPE;
		return resolveElementReference( module, prop, (ElementRefValue) value );
	}
	/**
	 * Resolves a property structure reference. The reference is the value of a
	 * property of type property structure reference.
	 * 
	 * @param module
	 *            the module information needed for the check, and records any
	 *            errors
	 * @param prop
	 *            the property whose type is structure reference
	 * @return the resolved value if the resolve operation is successful,
	 *         otherwise the unresolved value
	 */
	public StructRefValue resolveStructReference( Module module,
			ElementPropertyDefn prop )
	{