I work for 'a major software company.' I don't know how Invision, or any software company, can expect to sell new versions of its software if the user can't convert the old data to the new version. I'd expect Invision would provide a way to convert the data.
I'm much happier with this 'old' version of the Invision software than the new version of vBulletin (used by AAJ and Jazzcorner).
Isn't this stuff shareware?
http://www.invisionboard.com/download.cgi?subc=trial