If a menu with tbas is used, when an app has a link to open in a new tab in the menu, it works only if the link is one level deep, otherwise the new browser window.
If in amenu-tab there is a a form with a master-detail grid, the links in the grid open as new browser window no matter what.
Links open via a javascript functions, nm_gp_submit5 and nm_gp_submit5bis, maybe more I don’t know, in these functions, to open alink in a menu-tab it’s necessary to get the javascript function createIframe in the menu window.
To do this is used this code:
eval ("var func_menu_aba = " + sob_iframe + “parent.createIframe”);
If func_menu_aba is a function it’s possible to open a new tab in the menu otherwise you get a new winwdow.
My suggestion is to change that line in
eval ("var func_menu_aba = " + sob_iframe + “window.top.createIframe”);
in this way if the top most window is a menu you get a new tab in the menu, and doesn’t matter how deep is the item that has the link.