I also upgraded from 3.9.1 to 3.9.3 and ran into the similar problems people have been having. I have had none of the reported problems with LDAP, groups and memory leaks as other users reported until going to 3.9.3. I have my OpenFire server connected to my Active Directory using LDAP connection in the server console. My OpenFire server is running on Cent OS 6.5 with the most recent general release kernel - 2.6.32-431.17.1.el6.x86_64 #1 SMP.
OF Groups Missing in IM Client: I created object groups in AD specifically for the OpenFire server and linked my various staff and departments into those groups. Before 3.9.3 I had no problem with groups being pulled in from AD and disappearing in the IM client. Renaming the groups with removing spaces and special characters has so far worked but is a terrible solution to this problem.
Users Appearing Offline: I also experienced the issue with users appearing offline even though they weren't though their session was still active on the server. Expanding the vcard, username2roster and even the java memory size and caches all seemed to help but I still think there is an underlining problem.
Java Memory Leak: Also as I stated before I'm experiencing the memory leak now. I'm running the current java Cent OS 6.5 general release version 1.7.0_55, OpenJDK Runtime Environment (rhel-2.4.7.1.el6_5-x86_64 u55-b13), OpenJDK 64-Bit Server VM (build 24.51-b03, mixed mode). I changed my sysconfig file to point to the /etc/alternative/java link instead of using the OpenFire built in, However I'm still getting a constant memory growth in my OF admin console where the memory keeps growing from roughly 40 MB to 120-130 MB out of 592 MB total. Granted I'm not maxing out my java memory buffer but it's not normal behavior.
Granted this is a post that applies to several existing posts but I felt it might be better to group them up into one.