I have a mailbox on my server that 4 people connect to/share via their Outlook profiles (Under Open Additional Mailboxes "Advanced" tab in Exchange Props). Two users have Outloook 2003 and 2 have Outlook 2007 - the one with problem is running 2007, but another user with 2007 works fine.
The tasks for this mailbox are not showing up for 1 user.. it's like they are totally disconnected from the Tasks portion of this mailbox.. Calendar sharing works fine.. the inbox/emails are all fine.. just not the tasks for this one user.. they don't see anything, nor can they create any tasks that the other 2 can see..