Missing core dump from child process

All-

I have a child process that is not producing a core dump when it terminates. Here is what I have configured:
In etc/profile I have set ulimit -c unlimited
In etc/sysctl.conf I have set:
kernel.core_pattern=core.%e.%p
kernel.core_uses_pid=1
fs.suid_dumpable=1
The folder where the executable runs is writable, and there is enough space on my partition.

I kill the process logged in as root using 'kill -6 <child_pid>

Thanks,
Scott