This error happend to me when i runned a command on my Centos VPS.
audit_log_user_command(): Connection refused
And after some googling it seems that a lot of Centos users are running into this when executing SUDO.
But it seens that this is a bug in Centos kernel, and its not fixed yet.
My problem was that i was running the commands logged as root ( silly me ).
Hope you are too, because otherwise i have no sollution for you 
.
Cheers