Sub menu display issues since upgrade to 4.2.1

[Ross L]

Hi,

I've noticed on some themes the sub menu is broken during the upgrade from 4.2 to 4.2.1 (example attached). Any ideas on the cause / fix, as the theme creator has been AWOL for many months.

The additional CSS contains the following relating to the navbar:

/* Navbar
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
.navbar {
    background:{vb:stylevar nav_background};
    position:relative;
    height:{vb:stylevar nav_height};
    font:{vb:stylevar navbar_font};
    color:{vb:stylevar navbar_link_color};
    width:100%;
    padding:0;
    margin:0;
}
.navbarLeft {
    background:{vb:stylevar nav_left_background};
    height:{vb:stylevar nav_height};
}
.navbarRight {
    background:{vb:stylevar nav_right_background};
    height:{vb:stylevar nav_height};
    padding:0 9px;
}
#navtabs li.selected ul.floatcontainer {
    margin-top:{vb:stylevar nav_selected_margin};
}
#navtabs li.selected ul.floatcontainer a:link, #navtabs li.selected ul.floatcontainer a:visited {
    line-height:{vb:stylevar nav_selected_height};
    height:{vb:stylevar nav_selected_height};
}
.navbar a { color:{vb:stylevar navbar_link_color}; }
.navbar a:hover { color:{vb:stylevar navbar_linkhover_color}; }

.navtabs ul li:first-child {

}
.navtabs {
    padding-{vb:stylevar left}:0;
}
.navtabs ul {
    position:absolute;
    top:{vb:stylevar navbar_tab_size.height}px;
    {vb:stylevar left}:0px;
    width:100%;
/* This is to fix RTL menu issue under Opera */
        direction:ltr;
}
.navtabs li {
    float:{vb:stylevar left};
    padding-{vb:stylevar right}:2px;
    background:url({vb:stylevar imgdir_themedir}/navSplit.gif) no-repeat top {vb:stylevar right};
}
.navtabs li li {
    background:none;
}

.navtabs ul li {
    border-{vb:stylevar right}: 0;
    position: relative;
}
.navtabs li a {
    height:{vb:stylevar navbar_tab_size.height}px;
    line-height:{vb:stylevar navbar_tab_size.height}px;
}
.navtabs li a.navtab {
    display:block;
    min-width:{vb:math {vb:stylevar navbar_tab_size.width} - 2 * {vb:stylevar padding}};
    width:auto !important;
    width:{vb:math {vb:stylevar navbar_tab_size.width} - 2 * {vb:stylevar padding}};
    _min-width:{vb:math {vb:stylevar navbar_tab_size.width} - 0.5 * {vb:stylevar padding}};
    _width:auto !important;
    _width:{vb:math {vb:stylevar navbar_tab_size.width} - 0.5 * {vb:stylevar padding}};
    text-align:center;
    color:{vb:stylevar navbar_link_color};
    font:{vb:stylevar nav_font};
    text-decoration:none;
    line-height:{vb:stylevar navbar_tab_size.height}px;
    height:{vb:stylevar navbar_tab_size.height}px;
    padding:0 10px;
}
.navtabs li a.navtab:hover {
    background:{vb:stylevar navbar_tab_selected_background};
    color:{vb:stylevar navbar_linkhover_color};
}
.navtabs li.selected {
    color:{vb:stylevar navbar_linkhover_color};
    height:{vb:stylevar navbar_tab_size.height}px;
}
.navtabs li.selected a.navtab {
    color:{vb:stylevar navbar_linkhover_color};
    position:relative;
    top:-{vb:stylevar navbar_tab_selected_top_width}px;
    padding-top:{vb:stylevar navbar_tab_selected_top_width}px;
    z-index:10;
}
.navtabs li.selected li a,
.navbar_advanced_search li a {
    text-decoration:none;
    font:{vb:stylevar navbar_font};
    line-height:{vb:stylevar nav_selected_height};
}
.navtabs li.selected li {
    padding:0 5px;
}
.navtabs li.selected li li {
    padding:0 2px;
}
.navtabs li.selected li a {
    color:{vb:stylevar nav_selected_link_color};
    font-weight:400;
    padding:{vb:math {vb:stylevar padding}/5} {vb:math {vb:stylevar padding}/2};
}

.navbar_advanced_search li {
    height:{vb:stylevar nav_selected_height};
    display:block;
    clear:both;
}

.navbar_advanced_search li a {
    color:{vb:stylevar navbar_link_color};
}

.navbar_advanced_search li a:hover {
    color:{vb:stylevar navbar_linkhover_color};
    text-decoration:{vb:stylevar linkhover_textDecoration};
}

.navtabs li.selected li a:hover {
    color:{vb:stylevar nav_selected_link_hover_color};
    text-decoration:{vb:stylevar linkhover_textDecoration};
}

.navtabs li.selected .popupbody li > a {
    padding:{vb:stylevar popup_padding}px {vb:stylevar padding};
    text-indent: 0;
    color: {vb:stylevar navbar_selected_popup_body_a_Color};
}

.navtabs li.selected li a.popupctrl {
    -moz-border-radius:3px;
    -webkit-border-radius:3px;    
    border:solid {vb:stylevar lightweightbox_border.borderWidth}px transparent;
    _border: none;
    background:transparent url({vb:stylevar imgdir_misc}/arrow.png) no-repeat {vb:stylevar right} center;
    padding-{vb:stylevar right}:15px;
        _background-image:url('{vb:stylevar imgdir_misc}/arrow.gif');
    color:{vb:stylevar nav_selected_link_color};
}

.navtabs li.selected li:hover a.popupctrl.active,
.navtabs li.selected li a.popupctrl.active,
.navtabs li.selected li a:hover.popupctrl {
    color:#fff;
}

Any help would be greatly appreciated.

Thanks in advance.

Ross