Disabling gprof profiling, which would occasionally cause the program to die with an uncaught signal 27 (Profiling timer expired). I suspect that this reflects a bug in gprof and the way it juggles its signal handlers, and maybe has to do with threading used in the app, but it's easier to disable the switch than to find the gprof bug tracker and run the inevitable test on the latest gcc that I can't install.