i too have been experiencing these total system freezes on dapper, as per the other posters its happening with VESA or ATI configured in my xorg ...
after reading this thread -> https://bugs.freedesktop.org/show_bug.cgi?id=7154 i reconfigured my Xorg to not use MergedFB & so far i've had one week of running **touch wood** with no freezes (previously my dapper install would randomly freeze after anywhere from several minutes to several hours - rarely more) not sure if its the exact same bug but the symptoms tally. hope this helps some of you. ta mmc. -- [dapper] xrandr freezes the system (radeon, MergedFB) https://launchpad.net/bugs/47775 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs