I have just installed 11.4 and Libre Office 3.3.1 uses GTK front-end under 11.4. With OpenOffice.org 3.2.1 under 11.3 all was OK.
Yes, this is known to some extent. I have been providing a patched version of OpenOffice for Ubuntu and Debian for some time now; it might be a good idea to get upstream support for Trinity into the stock OpenOffice/LibreOffice sources at this point. Any volunteers to work through the red tape and get the Trinity integration officially supported?
Tim