This ticket is related to bug 186. It took quite a few days for this problem to surface again but this time I had two test accounts running with debug mode on.
The set up is the same as in bug 186: CentOS6 Linux OS, pidgin 2.10.2 clients with SIPE git head 7f921fb9. Two test accounts (systest2 and systest4) have very limited buddy lists and they have each other and themselves added as buddies.
The problem is that the pidgin clients will not report their status changes (or receive others') any more and get stuck in Available. Even after closing both pidgins, I still have systest2 and systest4 Available in my main pidgin (robert-sz).
Thanks for having a look at the logs!