We too have corrupted the 3300 database by programming via the CLI. Not only does Mitel Product Support warn against it, but 3300 I&M training school strongly cautions against it. The issue, as I understand it, is the 3300 has multiple operating systems, such as vxWorks, Express Messenger, sx2K call control, etc. and the GUI serves to orchestrate them all together. Programming performed via the CLI, under certain circumstances, does not get correctly propagated to the other platforms. This type of DB Corruption also does not show up in a DBMS Check, rather it manifests itself as weird unexplained problems requiring a full reinstall of software. Been there and done that.