A lot has changed between version 4 and version 5 of the forum. I just didn't have time to write an upgrade script, so everyone is going to have to do it on their own. If you're upgradingn from a previous version, don't forget to do the following things:
Most important, you'll need to redo the forum configuration. Versions prior to 0.5.0 stored all the configuration in the “fconf” table. This table is no longer used, since the forum configuration is stored in tt_content in the flexform field as XML. Once you install your forum, reconfigure it by editing the instance of the forum plugin. You'll see the same options, more or less, in the flexform – just reconfigure it.
You'll need to set the “general records storage page” value in the page header of the page containing the forum (edit page header -> general records storage page). Set this to whatever page you're storing your forum records in.
Unless you moved the mailer script out of it's default location, you'll need to edit the mailer.php file and add the correct “from” address for the mailer. I'll be abstracting the from address from the script in the next update so that you don't have to do this every time.
