Javascript error in Edit Mode

I think it's related to the menus.
My IE complains about this line:
<script language="javascript"> document.getElementById('tab_submenu_cms_top_menu_2').style.position ='absolute'; document.getElementById('tab_submenu_cms_top_menu_2').style.height= '220px'; document.getElementById('tab_submenu_cms_top_menu_2').style.overflow='auto';</script><li><a href="/c/portal/layout?p_l_id=32.1&p_p_id=EXT_11&p_p_action=1&p_p_state=maximized&_EXT_11_cmd=new&_EXT_11_inode=0&_EXT_11_struts_action=%2Fext%2Fcontentlet%2Fedit_contentlet&_EXT_11_referer=%2Fc%2Fportal%2Flayout%3Fp_l_id%3D32.1%26p_p_id%3DEXT_11%26p_p_action%3D1%26p_p_state%3Dmaximized%26_EXT_11_struts_action%3D%252Fext%252Fcontentlet%252Fview_contentlets&_EXT_11_selectedStructure=312645&lang=1">DOTCMS-1082</a></li>

Object Required.

This tab: tab_submenu_cms_top_menu_2 which we're trying to look for is not defined anywhere on the page.

This is working in demo so this must be something in trunk only.