Hmm...I guess that I would be concerned about the failure of the security audit...unless you know of known issues at that particular time. I'm used to seeing a string of Success Audit entries, but I'm not smart enough to properly interpret anything else.
Microsoft says, Failure Audit (Security log): An event that describes an audited security event that did not complete successfully. For example, a Failure Audit may be logged when a user cannot access a network drive.
From what I see on the Web...this event happens frequently enough...but I don't really see where anyone asserts that it is
or is not
something to be concerned about.
Since your IPSEC service is running...I suggest not worrying about it.
As a general way of checking all system files, I would run sfc /scannow. Sometimes these little hiccups are caused by missing or damaged files which don't necessarily result in an error message us common users can interpret.
How To Use Sfc.exe To Repair System Files - http://www.bleepingcomputer.com/forums/t/43051/how-to-use-sfcexe-to-repair-system-files/