[CentOS] /etc/passwd aand /etc/shadow out of sync on 4.6 box

Fellow list members,

I recently tried to add a user to a little used server that hadn't see a change in users for quite a while. When I use system-config-users I get an error alert that says -

The user database cannot be read. This problem is most likely caused by a mismatch in /etc/passwd and /etc/shadow. The program will exit now.

I awk'ed out the user ID's and ran diff. That came back with the shadow file having two more users than the passwd file. Ok, fine, whatever. But the trick now is how to fix this. Can I just use vi and delete the offending lines from the shadow file? Is there a utility or script that will sync them in a less potentially destructive way?

Any pointers to info on this are greatly appreciated.

Thanks, Joe