Bug 135265 Paste to a wrong column
Steps to reproduce: 1.Open the attached file 2.Choose the column[2] which contains a label , copy and paste to column[3] Expected result: It will be pasted to column[3] Actual result: It is pasted to column[4] The related bug is #103448
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/ReferencableStructure.java
* 
	 * @see org.eclipse.birt.report.model.core.IReferencable#addClient(org.eclipse.birt.report.model.core.DesignElement,
	 *      java.lang.String)
	 */
	public void addClient( DesignElement client, String propName )
	{
		clients.add( new BackRef( client, propName ) );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.IReferencable#dropClient(org.eclipse.birt.report.model.core.DesignElement)
	 */
	public void dropClient( DesignElement client )
	{
		for ( int i = 0; i < clients.size( ); i++ )
		{
			if ( ( (BackRef) clients.get( i ) ).element == client )
			{
				clients.remove( i );
				return;
			}
		}
		assert false;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.IReferencable#getClientList()
	 */