can't change user data or passwords!!!!

[gschlut]

this is strange. I cannot change any user data or passwords for any account. if I do a passwd 'useraccount' to change the password it will just sit at the command line. I also tried using usermod with the same results. Nothing in the logs and all users can log in fine. I just can't change any user information. Any ideas

[Ashcrow]

What distro and when did this start? Any packages installed/system changes just before this happened?

[gschlut]

I am using RedHat 7.1, and the only change made was a reboot so I could replace a fan that went out today. That is why it is so odd. I have just a few user accounts on this server, all of the other accounts are stored on another server and accessed via nis. These local accounts are for our legacy I.S. system, and are the only ones having problems.