sorry guys i cant downgrade so far as i know, if you have algodoo upgrade it, and if you have phun then oh well. And no none of my scene's are phun compatible becuase i always use lazer's, mostly for scripting, so get over it.
yes, all old scene's work with Algodoo 1.7.4, of course there is glitches but you can work around them. If you have a problem after updateing you can ask me.