After I deleted a bunch of old emails in MS Outlook 2011 for Mac all my Contacts disappeared and most of my Calendar appts,  Email was OK.  Tried rebuilding the DB but it failed with error 18000.  Tried restoring DBs from Time Machine - but all DB rebuilds fail with error 18000.  What can I do?  My DB is 1.5 GB and I have 35 GB of free space on my MBA.  This sucks.   I see that a bunch of other people have had similar issues - sounds like a software problem.