On Tue, 2016-06-14 at 18:32 -0700, CLOSE Dave wrote:
When I leave my desk, I lock the screen but I disable locking based on inactivity. As long as this works, I'm happy.
Obvious question: Just a simple screen lock, or is there a screensaver running (some of them were terrible at crashing X)?
I'd try a different screensaver, or screen locking program, just to see if that's the actual cause.