My wife has 3 pop3 accounts in her Outlook 2011 for Mac with rules that move emails from the inbox to inboxes for each account.  One of the accounts now needs to be IMAP.  I created an IMAP setup for this account.  Now when we do a send/receive all, all "sub folders" disappear in the "On My Computer" folder along with the |> icon in front of it.  We do not have group all like folders nor do we have hide folders on my computer.  The only way to get them back, visually and accessibly, is to shutdown Outlook and restart it.  We are fairly up-to-date with Office 2011 updates.