When I have celestia running in a window, closing the window kills X, I have to wait for it to restart, then log in again.
Actually this seems to happen with a lot of graphics intensive programs, perhaps the nvidia binary drive is to blame. Backtrace:0: /usr/bin/Xorg(xf86SigHandler+0x81) [0x80c2d21] 1: [0x74e420]2: /usr/lib/xorg/modules/extensions//libGLcore.so(xmesa_check_and_update_buffer_ size+0x32) [0x1018cf2] 3: /usr/lib/xorg/modules/extensions//libGLcore.so(XMesaResizeBuffers+0x29) [0x101b489] 4: /usr/lib/xorg/modules/extensions//libGLcore.so [0x101b810]5: /usr/lib/xorg/modules/extensions//libglx.so [0xd993ba] 6: /usr/bin/Xorg(compPositionWindow+0x59) [0x8105599]7: /usr/bin/Xorg(ReparentWindow+0x1ac) [0x8077b6c] 8: /usr/bin/Xorg(ProcReparentWindow+0xd5) [0x8089425]9: /usr/bin/Xorg [0x81523c1] 10: /usr/bin/Xorg(Dispatch+0x1aa) [0x80899fa]11: /usr/bin/Xorg(main+0x495) [0x8071735] 12: /lib/libc.so.6(__libc_start_main+0xe0) [0x5a9f70] 13: /usr/bin/Xorg(FontFileCompleteXLFD+0x1e9) [0x8070a21] Fatal server error:Caught signal 11. Server aborting
If you are running the nvidia proprietary driver, you need to report this to nvidia. Unfortunately, there's nothing I can do. If you can reproduce the problem with another card/driver, please reopen this ticket.