I had the same symptoms after updating from OOo in Squeeze to the current LibreOffice in squeeze-backports. Existing and new users, with or without existing ~/.libreoffice, would just see a half-second of splashscreen before a segfault within libsofficeapp.so occurred. root, however, could always work without problems. After much browsing through strace output, I found that /etc/opt had wrong permissions: it was 700 and should have been 755. After giving the right permissions to this one directory, everything worked. Sorry to not be able to provide more details; this happened some weeks ago on a system I don't have regular access to. Just thought to share this in case it helps someone. Happy New Year, Viktor.
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