Automatic UV Live Unwrap in 2.49?

I know how to do automatic live unwrapping in 2.5/6 but I still do some work in 2.49 where live unwrapping only seems to work when pinned vertices are moved. However, in the release logs for version 2.42 there’s this page:

http://www.blender.org/development/release-logs/blender-242/uv-unwrapping/

…featuring a video that shows fully automatic unwrapping as seams are being set:

http://download.blender.org/demo/movies/seamcut_blender242.mov

Was this a feature of the old UV Face Mode, no longer available in 2.49? Or is there still a way of working like that in 2.49?

I think the unwrapping code was slightly different back then, it was called ‘LSCM’.