The problem appears to be related to an incompatibility with LibreOffice and the MS Office IFilter pack. When LibreOffice is installed although the MS Office IFilters objects can be created they do not appear to be able to load any documents.
The simplest solution is to simply 'Repair' the LibreOffice installation via the Add/Remove Programs control panel settings. This should reset all the registry settings to point back to the LibreOffice IFilters.
The registry points to the appropriate IFilter for a given file type. If you look at the registry key for ODT files:
(default) value will point to the registry key to look at for the IFilter settings. For MS Office it points to:
and for LibreOffice: