I have the same problem that is already mentioned here https://askubuntu.com/q/187053 but I don't find the answers to that question useful:
I just bought this computer (one week ago) that comes with Ubuntu 12.04 and libre office 3.5.4.2 and I'm not that happy with Libre Office, because I have been crushing several times, closing itself and I need to recover my documents, but the last issue was the same as HU23 mentioned. Suddenly the window preview disappear and every time I click on the libre office icon on the side bar it opens a new window. What do I get the bird-eye view preview again and avoid this problem?
If it's the Writer Logo, well there's the answer, you're starting LibreOffice Writer which starts with a blank document. If it isn't well, I'm not sure then.
– RPiAwesomeness May 30 '13 at 19:39