4
in short, no.
well not easily anyway from what i can gather.. i tried this a long while ago and couldn't get it to work correctly either..
everything kept loading up inside each frame..
you would need to edit quite a few of the core files and change the way it reads the theme & template files, however i can't tell u anymore about that as i haven't the knowledge to be able to tell you what to edit etc..
i had the same prob with invisionboard ages ago, and invision also informed me that it would need editing and changes made to lots of files and wouldn't be a quick or simple task.