I seem to have run into ventrical's smirched character problem. It started after the compiz updates over the last couple of days. I was using the nvidia-331 binary driver, and I've also tried nvidia-331-updates, and the problem hasn't been solved. I'm currently running the nouveau driver, but I very occasionally get a hard lockup, that only a cold reboot will solve.
This installation was fresh when the toolchain was uploaded, and I was hoping to run it all the way through this development cycle, but I am willing to create a new install on another partition just to see if it is because of kruftiness on the original installation.