Comment 112 for bug 956071

1.6.2-1ubuntu1~precise2 which I think has this patch, and also 1.5.99, continue to crash for me with this SEGV on occasion, shortly but not immediately after unlocking the screen (not necessarily after resume from suspend). No clear way to reproduce. Anything that can be done to help? (Any all-in-one instructions available for rebuilding X + drivers with symbols and running through Valgrind?)