how to reimport mediatomb after config changes

I have a few M2TS files that mediatomb does not recognize. It associats M2TS files with application/octect-stream mime type. Consequently my upnp clients don't play these files. I updatd /etc/mediatomb/config.xml to map M2TS file extentions as video/mepg mime type. Restarted mediatom server. Restarte cored. Config.xml changes didn't take effect. According to mediatomb documenation, those files need to be reimported. I would rather reimport all of my media files. If it was sqlite.db, one way to reimport is to to delete the db and mediatomb will recreate it. However, we use mysql. Do we have to delete rows in pluto_mediatomb db ? If the whole thing I did was wrong, what is the right way to solve this problem. Thanks in advance.