Comment #17 on issue 99 by dorma...@rydia.net: Memcached 1.4.2 server segmentation fault
http://code.google.com/p/memcached/issues/detail?id=99
Is this still on gentoo? Which php client are you using and at what version?Any chance you could run the memcached-debug program under gdb and kill it a few times while collecting backtraces? Curious to see if it's always in the same spot.