I have two issues with Outlook users - probably only 2007 and above, but I haven't tested 2003 - the Offline Address Book will not sync completely and Out of Office is still unavailable. For Outlook 2007 users, send/receive is hanging at 33%.
Do I need to change permissions on these folders in IIS to get things going? I read through some articles about opening up authentication and "ignoring" SSL for EWA and OAB (which I just set), but it hasn't resolved yet.
I haven't tried all of the alternatives in that article just yet...but that's my starting point for troubleshooting.