Thanks, this worked well, and solved my problem. I started to get the dreaded error "Microsoft Sync Services has found an Error. And will close". It caused some sort of memory leak, and each time it slowed my Mac down by adding 20Mb to its memory needs. It was hard to find the solution: I shut down sync services on Entourage, and still got it. Deleted all contacts in Entourage - and still got it. Eventually I found the problem. There was some sort of corrupt entry in the address book, which showed up in the count of contacts, but would not show up in the list - and it was impossible to delete it. I worked hard to rebuild index but it did not fix. So I abandoned that identity, using it just as an archive and moved over what I needed using your tips above. Now I have new working identity that syncs again with ical, address book and my iphone. Microsoft, if you are reading this, please find a way of allowing users to "flush" the entire address book when needed. I suspect the calendar might also have same issue.