I migrated a client from SBS/Exchange 2000 to Exchange 2003 this weekend. On the server-side, everything went quite smooth, despite my fears that SBS would really screw with my ability to work with the standard Windows and Exchange tools. Not so much on the client side.
All the clients were running Outlook 2003. Some users were seeing duplicates of many of their system-level folders (Inbox, Calendar, etc). All users were unable to access any folder but their Inbox. Trying to view the calendar, contacts, or even a user-created mail folder would cause Outlook to crash. I suspected it had something to do with offline folder files, although deleting the Outlook profile and it’s associated OST files had no affect. A bit of Googling finally turned up this post at joeware, which pointed to this post in the Microsoft newsgroups, which contained the answer.
After some work, we were able to determine why Outlook 2003 crashes after moving mailboxes off of Exchange 2000 onto Exchange 2003. The fix is to add a registry value â€œGuid-Replid Cachingâ€ under HKLM\System\CurrentControlSet\Services\MSExchangeIS\SERVERNAME. Under each mailbox store we added a REG_DWORD of â€œGuid-Replid Cachingâ€ with a value of 0.
Taking their advice, I made the change, restarted the Exchange IS service, and damn if that didn’t solve the problem.