Safe Shutdown

I am running several turnkey linux servers (mediawiki, fileserver, etc).  I recently started playing around with concrete5, and am having a minor issue.  All of my other turnkey systems will shutdown safely when I send a "shutdown signal"; but when I do this for concrete5, it just sits there.  I have to "Power off" the machine to turn it off.

Why can I not shut it down properly?  Is there a better way?

I realize that shutting down reguarily is abnormal, but the page is in development (and is currntly virtualized on my laptop), so regular shutdowns as I move around are required.

Thanx

Bryan