The modifications in xorg.conf as suggested by @Ste_it do not help for a ATI X700 (RV410)
Any application that requires 3D, including screensavers, glxgears and even glxinfo, will freeze the system instantaneous. Who is on this bug and what do you need? Please ask! -- Screensaver freezes on Dapper (ATI Radeon 8500 LE) https://launchpad.net/bugs/38181 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
