This happened to me and could be reproduced reliably when inserting a picture in a text document, then trying to insert another. Upon selecting "Insert → Picture → From File..." the second time, the file dialog does not open, instead Writer freezes and .xsession-errors gets flooded.
Removing the lo-menubar package "fixed" the problem.
Ubuntu: 12.04 LTS
libreoffice-writer: 1:3.5.4-0ubuntu1.1
lo-menubar: 0.1.0-0ubuntu4
This happened to me and could be reproduced reliably when inserting a picture in a text document, then trying to insert another. Upon selecting "Insert → Picture → From File..." the second time, the file dialog does not open, instead Writer freezes and .xsession-errors gets flooded.
Removing the lo-menubar package "fixed" the problem.