Yo, 'stable' tree from dustin has a commit (5a44468) which disables the AI_ADRCONFIG flag unless -l is specified. This causes memcached to not start on machines without ipv6 configured unless you specify the -l option.
I ... don't have a testbed onhand to figure out the original intent of the patch (make memcached start with no networking configured?). Before I back out the change, anyone else know how to fix it properly? Thanks, -Dormando