Code customizations are unsupported. However, the following solution may work:
1. Copy $NX_ROOT\bopcfg\www\wwwroot\scripts\menus.js to $NX_ROOT\site\mods\www\wwwroot\scripts
2. Edit $NX_ROOT\site\mods\www\wwwroot\scripts\menus.js
3. Remove the conditional from the last block of code in the function "MenuBar.prototype.add_toolbar_icon". That is, instead of this doe:
if (ahdframeset == ahdtop) {
_td = doc.createElement("TD");
_td.className = "menulist_unselected_background";
_td.width = "100%";
bar.appendChild(_td);
}