In case you haven't seen it yet, the Domino Server Release 8.5 Interim Fix 5 is available. You can find more information in this document, Readme for IBM Lotus Domino Server Release 8.5 Interim Fix 5 (85IF5)...

Source: http://www-10.lotus.com/ldd/nflsblog.nsf/dx/lotus-domino-server-release-8.5-interim-fix-5-85if5-is-available