I wasn't going to keep updating older releases of Ubuntu but I'm getting a lot of complains from such people. Older version of Ubuntu which uses GTK2 the new version of RSW won't work at all and it may crash as the 2 versions of GTK are uncomplatible. The system call that RSW makes to change the wallpaper, etc are basically the same.
Also, older verions of RSW except 4.2 won't work either as the call the access the pictures has changes.
Last Friday I pushed an update into the Natty repository of Ubuntu to back port RSW back to GTK2, I'm still not 100% sure if this version is fully working. Once I have an updated version of RSW working for GTK2 I'll push the release to all the other Ubuntu releases from Lucid upwards via the ppa.
Today, I will package a debian installer for releases of Ubuntu using GTK2 and post a link in this post, if you are interested on this version of RSW and which to give a hand by trying them out comment on this post the recieve updates.
Thank you