We have recently migrated from Small Business Server 2003 to Exchange Server 2010 SP1 (update rollup 6). All updates have been run on the new Exchange server. The Small Business Server has been completely removed from the domain and is no longer running. The new Exchange Server is running on Windows 2008 R2 Standard x64 on Citrix XenServer 6. 90% of the users are running on thin clients that connect to a 2003 Windows Server x86 Terminal Server also on Citrix XenServer 6. Outlook 2003 is running on the Terminal Server in non-cached mode. Outlook is generally very responsive and running well. When users add, move or remove an appointment in a public folder calendar the appointment takes about 1-3 minutes to show the change in Outlook. Here are some examples that I have been able to create. User 1 - Admin (Terminal Server, Outlook 2003) User 2 - User (Terminal Server, Outlook 2003) User 3 - User (OWA) User 1 creates an appointment in the Meetings public folder 1:55pm. User 2 is already looking at the same calendar. User 1 and User 2 see the appointment finally shows the addition at 1:57pm. User 3 logs into OWA at 1:56 pm and it already showed the appointment being deleted. The appointment is then deleted at 1:58 pm by User 1. User 2 is still looking at the calendar and still sees the appointment. User 2 clicks on another public folder then comes back to the calendar and the appointment is gone at 1:59 pm. User 1 still sees the appointment until 2:01pm. It appears that this is all just a refresh issue with Public Folders in Outlook 2003. Any help is appreciated.

I just found the answer to this in case anybody else is having the same issue. http://support.microsoft.com/kb/2009942

See if that works or not, I believe you ave to apply SP2. This fix is in there. You're on RU6 that fix should be in RU6, unless you didnt do the reg key, even so, I believe that the fix was removed from RU3 anywat but is back in SP2.Sukh

I had to add the reg key and now it is working.