Comment 2 for bug 831336

Are you using lightdm or gdm?

Can you attach your .xsession-errors file from after reproducing the bug?

You mentioned the regression started just recently; could you narrow down on a date range? We haven't had much change in X, so it's possible the bug is due to something else; knowing roughly when the regression started we can examine your dpkg.log to see what might be causing it. I'm attaching a parsed list of packages that you upgraded in the past couple days.

I notice there was a kernel upgrade in this period; you could try booting into 3.0.0-8 and see if you can reproduce it there (hold down the left shift during boot to bring up the kernel boot menu).