We are migrating from Exchange 2003 to 2010. We currently have just a couple of hundred users on 2010 with approx 1000 to migrate still on 2003.Today a ticket was opened that users were not seeing the correct free/busy time of a Director when setting up a meeting.
I checked the accounts and the Director is on Exchange 2010, the other user is on Exchange 2003. I tried opening the 2003 account in its own profile on my computer and then looked at the Director's calendar and the free/busy is wrong on my computer so I know it is not a time zone issue of any kind.
From my account on the 2010 server the Director's free/Busy is correct. I tried looking at it in the profile of a test account on the Exchange 2003 server and it is wrong there too, so it isn't limited to the one user's email account, but it is limited to accounts on Exchange 2003 which constitutes the majority of accounts right now.
I have public folders replicating successfully to the 2010 server including the system folders.