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/Module.java
* Looks up an element given an element ID. Returns null if no element
	 * exists with the given ID. Also returns null if IDs are not enabled. Note:
	 * this method will not find an element that has previously been deleted
	 * from the module, even if that element still exists in memory in
	 * anticipation of issuing an undo of the delete. That is, only valid
	 * elements can be found.
	 * 
	 * @param id
	 *            The id of the element to find.
	 * @return The element itself, or null if the element can't be found or if
	 *         IDs are not enabled.
	 */
	public DesignElement getElementByID( long id )
	{
		if ( idMap == null )
			return null;
		return (DesignElement) idMap.get( new Long( id ) );
	}
	/**
	 * Returns the undo/redo stack for this module.
	 * 
	 * @return The "command" stack.
	 */
	public ActivityStack getActivityStack( )
	{
		return activityStack;
	}
	/**
	 * Preprares to save this module. Sets the modification date.
	 */