Something that might be interesting to note: I've had the "compositing window manager" option turned on, and had the panels at around 28% transparency. I've since turned both things off (due to my experiments related to https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=884116).
Since I don't know how the crash is triggered, I don't know whether this helps or not. I haven't had it happen yet, but I've previously gone quite a while without a crash. Regards, Agafnd
