At least reproducible in combination with firefox-16.0.2-1.fc17.x86_64: With the npsoplugin enabled (see <http://wiki.documentfoundation.org/Npsoplugin>), open a ODF file in Firefox (so that soffice is started in background and displays the document inside Firefox), then in start "soffice" in parallel: This returns immediately and does not show the LO start center. (If you pass any arguments to "soffice" to open new or existing documents, this works fine, passing the request on to the soffice already running in background, which displays the requested document in a proper window outside Firefox.)