I've been experiencing severe stability issues for the past couple days, and I've narrowed it down to being a part of X, since everything goes back to normal for a bit when I restart lightdm.
I use one of those video driver PPAs that builds packages right from git, which I know is at my own risk. I've already tried using synaptic to force a version of xserver-xorg-intel from a more stable PPA, and that didn't have much effect, but the version of libdrm currently in the repo dates from the same time as these problems began, so I imagine that's the culprit. However, when I try to use synaptic to force a stable version of the various libdrm packages (-intel and :i386 and so forth), it warns me that virtually every application in my system that depend on X will have to be removed as well. Needless to say, I don't want to have to do this. Do I have a reasonable option other than waiting for the PPA (oibaf, if anyone's curious) to update again?
Unfortunately, I already did an apt-get clean when I thought the stability issues might be due to dpkg corruption, so I don't have a slightly older version locally to revert to.