I have had a few of those. I recall we had one setup where when apache crashed, it screwed up the PID file, so when you did an apachctl call, it listed the service as already running, but it wasn't.

This morning at 01:01:09 my apache error_log displayed the above. I have noticed several requests from 64.152.75.91 for the file robots.txt in my root directory. Today this hack attempt occurred ...