interestingly, installing rss-glx seems to stop this problem, at least with the openGL screensavers.
** Bug 48684 has been marked a duplicate of this bug -- OpenGL viewport cut-off with 915gm graphics https://launchpad.net/bugs/43052 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
