Anyone ever get a "interrupted by signal 10 (bus error)" when rendering with Mental Ray? I rendered an AO pass a few minutes ago and it finished...when I went to File->Load Pass, that error came up and the AO pass won't load.
It's an error caused by mental ray tries to access an invalid memory address. It's pretty rare. A segmentation violation (signal 11) is more common. You should log a bug. A (temporary) fix can be to reboot the machine. You may never see it again. If it persists, your scene database may have gotten corrupted.