I'm using Ubuntu 12.10 with the latest updates installed, and the global menu works in LibreOffice, even if it is a bit buggy.
However, I can not use the HUD with LibreOffice. No matter what I search for, it only finds the menu entries from the indicators.
I also tried lo-menubar, that I think wasn't as buggy as the standard implementation of the global menu, but it doesn't work with the HUD either.
In every other application, the HUD works fine. Where does this come from?