I think it would be useful if the clipboard contents were retained on application exit - this currently doesn’t seem to happen on Ubuntu 14.04/LO 5.1.1.2 Build ID: 1:5.1.1~rc2-0ubuntu1~trusty
If you run dpkg --get-selections | egrep '^libreoffice.*\t*install$' | sed 's/\t*install//g' (that’s a single line) or aptitude search ~ilibreoffice, what’s the package listing you get ? Use a pastebin or similar.
This is an issue with a difficult history, mostly unrelated to LO. Refer bug tdf#48783, especially comments 5 and 13 and the related Ubuntu links.