I believe the change for OF-764 may be adversely affecting memory utilization in some circumstances. Can you confirm whether you have significant MUC traffic (or history) with rooms that have conversation logging enabled?
The change I made was to load full history for MUC rooms by default rather than limiting it to two days, and also provided a new system property ("xmpp.muc.history.reload.limit") to optionally limit the history to a given number of days. I am planning to modify this slightly for the next release to restore the original limit of two days by default, while still allowing an override via the system property.
Note that this issue would only affect deployments that use MUC rooms with conversation logging enabled.