As discussed on the fop-user mailinglist with the thread http://marc.theaimsgroup.com/?l=fop-user&m=105233531123857&w=2 when there are nested lists be it ordered or itemized FOP's interpretation causes the list items to be placed wrong, where as the same document comes out correctly with RenderX. FOP uses the space-before attributes in all cases, even when they are within a list-item-body.
Bug fixed in latest Trunk (rev 584703), and probably in FOP 0.94
batch transition pre-FOP1.0 resolved+fixed bugs to closed+fixed