Sorry for the long delay, but I today upgraded to jaunty (RC) and the freezes still occure. In addition a freeze while browsing the web using epiphany occured. Browsing the web was stable while still using 8.10. I also attach a Xorg.0.log.
** Attachment added: "Xorg.0.log" http://launchpadlibrarian.net/25701052/Xorg.0.log -- [RV530 X1600] system freeze with gksu https://bugs.launchpad.net/bugs/329159 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs