Well i think i've found the problem. I don't know why, but i've found the option "Render Accel" active in my xorg.conf... I've changed "true" to "false" and now its OK. Thank you
-- Radeon driver RV280, x crashes https://bugs.launchpad.net/bugs/248719 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