I upgraded to Ubuntu 12.10 Quantal Quetzal about two weeks ago. As usual, there are a number of new or improved features and changes, the arguably most controversial being the Dash’s Amazon integration. What has not changed, unfortunately, is the problem of the global menubar in LibreOffice. Even more unfortunate, the temporary solution using “unity –reset” I wrote about before does not work anymore.
In Ubuntu 12.10 Compiz and Unity are using Gsettings instead of Gconf and because of this, the “unity –reset” command used to reset Unity doesn’t work anymore. This post explains how to reset compiz and Unity in Ubuntu 12.10.
You might also want to check out the concerning bug report on Launchpad. In the comments, a few tips are given about how to deal with LibreOffice’s disappearing global menu till a permanent solution is found. The problem is mostly with documents opened directly from nautilus. A ‘solution’ therefore is to first open an empty LibreOffice document and then the document you want to work on.
For those in the habit to open their documents from your file manager (and who doesn’t at least once in a while), there luckily is a less annoying fix. Everytime the menu is gone, you just press the Alt key twice. It works for me, but I have to repeat it for every new window, and sometimes for the same window after some time.
A more permanent workaround is to disable the global menu altogether. You can do this by removing the package “libreoffice-gtk”. The side effect is that this also removes all theming, which doesn’t make LibreOffice look any prettier.
All in all, with the Alt-Alt ‘solution’ this isn’t a deal breaker for me yet, but it ain’t pretty.

You can run libreoffice first and then open the file. This should work
Yes, that was one of the suggestions. But first having to open the Libreoffice just isn’t always terribly convenient. I can personally live with it, but it might be a show stopper for new users.
This doesn’t work for me. Most of the menu-items in Libreoffice cannot be used in Ubuntu 12.10 (try to insert an endnote). Only the options which can be reached by right click can be used. Unity seems unstable with other applications too, with nervous flickering of the < symbol. I hope this will be fixed soon.
Most works for me, but you are right, it all seems a bit buggy
Another workaround is to revert to classical, window based menu’s for all applications. This still yields a polished, integrated though slightly more classical experience. Complete removal of the global menu is done with “sudo apt-get remove indicator-appmenu appmenu-gtk appmenu-gtk3 appmenu-qt”. Use “install” instead of “remove” to revert the changes.
Certainly an option. I was quite sceptic about the whole idea behind the global menu, but I must be honest, I got to appreciate it, so it is a bit of a shame to give that up completely because of one program.