It would appear that a file, or some files, are not informing Secunia PSI 2.0 that LibreOffice is fully up-to-date and it seems Secunia is 'seeing' version 3.5.0.102 instead of version 3.5.1, so it thinks LibreOffice is out-of-date and insecure. Please discuss with Secunia what the problem is so thet either you or they can correct it.
*** Bug 47841 has been marked as a duplicate of this bug. ***
*** Bug 47926 has been marked as a duplicate of this bug. ***
@michaels.perry: Seems to be resolved → http://secunia.com/community/forum/thread/show/12365/update_to_3_5_1_not_acknowledged [See comment by Jais Vemmer, Secunia PSI Support, 27th Mar, 2012 10:19]