Comment 6 for bug 773065

and here some output from $ dmesg that might (or might not) be relevant.

[65656.709087] compiz[15321]: segfault at 19 ip 00007fdc502a7394 sp 00007fffdaa0f1e0 error 4 in libpthread-2.13.so[7fdc5029e000+18000]
[65753.562733] compiz[16046] general protection ip:7fe52e85a394 sp:7fff7b3235e0 error:0 in libpthread-2.13.so[7fe52e851000+18000]
[66187.972129] compiz[18408] general protection ip:7fbaa1f62f45 sp:7ffff6074f08 error:0 in libglib-2.0.so.0.2800.6[7fbaa1f22000+ed000]
[68191.787683] compiz[26407]: segfault at 0 ip 00007f21b81bcea9 sp 00007fff6d9ba210 error 4 in libwall.so[7f21b81ac000+24000]
[68515.598511] compiz[27613]: segfault at 58 ip 00007fb6729f1c51 sp 00007ffff62a4fd8 error 4 in libnvidia-glcore.so.270.41.06[7fb671a5f000+144e000]
[68572.300079] polkit-gnome-au[27200]: segfault at 48 ip 00007fbf379669d8 sp 00007fff4e054f40 error 4 in libglib-2.0.so.0.2800.6[7fbf3793f000+ed000]
[68624.361108] compiz[28602]: segfault at 58 ip 00007fda3ebfbc51 sp 00007fff2cd1d848 error 4 in libnvidia-glcore.so.270.41.06[7fda3dc69000+144e000]