We are having the same issue.
BIM Server (Build 3235) installed on Mac OS X Server 10.6.2. Mac OS X 10.5 and 10.6 Clients using ArchiCAD 13 (Build 3235) accessing it.
Was working very well, since November 2009. Within the last week (possibly as a result of the latest security update from Apple) we have begun having the same issue - BIM server stops every 10 seconds, checking connection or pressing 'Start Server' in BIM Server Control Centre starts it but it then stops again, making the server completely useless and locking all of our project information away on the server, again unusable.
I have tried, uninstalling, reinstalling etc etc but still have the same issue.
There are no users with % in the name, the mailserver is mail.djdgroup.co.uk and so does not contain _, and the server name xserve.djdgroup.co.uk is fully resolved and reverse DNS lookup works fine.
Any suggestions please - this is a major issue.
