Comment 8 for bug 874218

The x-1.log in the tarball has

"Backtrace:
0: /usr/bin/X (xorg_backtrace+0x26) [0x460566]
1: /usr/bin/X (0x400000+0x64b7a) [0x464b7a]
2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f714098e000+0x10060) [0x7f714099e060]
3: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f713b059000+0xe17d7) [0x7f713b13a7d7]
4: /usr/lib/xorg/modules/libwfb.so (wfbBlt+0x154) [0x7f713a3cd554]
5: /usr/lib/xorg/modules/libwfb.so (wfbOddTile+0x170) [0x7f713a3de600]
6: /usr/lib/xorg/modules/libwfb.so (wfbFill+0x54d) [0x7f713a3d2d9d]
7: /usr/lib/xorg/modules/libwfb.so (wfbPolyFillRect+0x1c4) [0x7f713a3d3574]
8: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x7f713b059000+0x463baf) [0x7f713b4bcbaf]
9: /usr/bin/X (0x400000+0xde915) [0x4de915]
10: /usr/bin/X (miPaintWindow+0x1a0) [0x45b590]
11: /usr/bin/X (miWindowExposures+0xc2) [0x45b752]
12: /usr/bin/X (0x400000+0x13486d) [0x53486d]
13: /usr/bin/X (miHandleValidateExposures+0x68) [0x5651e8]
14: /usr/bin/X (UnmapWindow+0x240) [0x457370]
15: /usr/bin/X (DeleteWindow+0x2b) [0x4573cb]
16: /usr/bin/X (FreeClientResources+0xdc) [0x44ea4c]
17: /usr/bin/X (CloseDownClient+0x5a) [0x42f05a]
18: /usr/bin/X (0x400000+0x2fae7) [0x42fae7]
19: /usr/bin/X (0x400000+0x232fe) [0x4232fe]
20: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xed) [0x7f713f8ca30d]
21: /usr/bin/X (0x400000+0x235ed) [0x4235ed]
Segmentation fault at address (nil)"

the issue seems rather an nvidia driver one then a lightdm bug then...