In Enterprise Manager, right click your database, choose properties and on the options ensure that auto close and auto shrink are selected. If you still have a problem, on the transaction log tab of the properties window check the box which allows you to restrict file growth to a maximum size. Although I don't use SIMS, I have had CMIS running with these settings for several years with just the auto close and auto shrink options. Although the database itself is around 1GB the transaction log is only around 1MB.