Comment 38 for bug 276782

I'm not sure where to post this, but I've been switching yesterday from Karmic to Lucid (upgrade of Kubuntu) and I have a X1250 on a Medion E1315 netbook (1366x768). I noticed serious instability after upgrading. VT switching crashed X and trying to run KRandR crashed X immediately on startup of KRandR. On Karmic, I had KMS swithed on (at least I never did anything to switch it off), and no regular crashes, but on Lucid, X was too unstable. I switched kernel mode setting off by adding options radeon modesetting=0 in /etc/modprobe.d/radeon-kms.conf and running update-initramfs -u afterwards. This solved all the stability problems. I've not seen a single crash after that. It seems that X is even faster than before.

What I wonder about is why KMS is enabled on ATI if there are still so many problems with it. X on an Ubuntu desktop should be (almost) completely crash-free. You know, the very reason why I use Linux and not Windows is that Windows always crashed in the video drivers...