Very slow groups-summary.jsp

My Wildfire 3.2.3 install (since duplicated in Openfire 3.3.0) loads groups in the admin interface (groups-summary.jsp) incredibly slowly (see http://www.igniterealtime.org/forum/message.jspa?messageID=143673 for more details).

I’‘ve dug into the code a little bit and extracted the relevant group loading bit from LdapGroupProvider and run it separately and it runs perfectly quickly, so where should I be looking? I can’'t really see what else is going on. Any ideas anyone?