A new beta revision is available.  Role Scoper 0.9.11 corrects problems with the internal cache which were preventing the modification of existing Page/Post roles and “exclusive role” settings.  Also corrected is a version detection glitch which (as of version 0.9.10) would have prevented first-time Role Scoper installations from using WP Role Metagroups.

Thanks to Julien for the bug report.