[Lynne]

The arrow is in the CSS:

tr.ygtvrow:hover td.ygtvcontent {
    background: {vb:stylevar vbcms_navwidget_menuitem_hover_background.backgroundColor} url({vb:stylevar imgdir_cms}/hover_arrow-{vb:stylevar right}.png) {vb:stylevar right} 50% {vb:stylevar vbcms_navwidget_menuitem_hover_background.backgroundRepeat};
}

So just write some custom CSS to remove it:

tr.ygtvrow:hover td.ygtvcontent {
    background: {vb:stylevar vbcms_navwidget_menuitem_hover_background.backgroundColor} ;
}