[CentOS] NetworkManager turned off yet clobbered yp.conf on boot?

A system had a disk problem, I took out the disk, mounted on another
system, tweaked around until I thought the disk problem was fixed, then put
it back in the original system. I did not edit any config files among the
tweaks. When I booted the system, NIS was not working right. I found that
these files had been changed: /etc/yp.conf /etc/resolv.conf /etc/ntp.conf
/etc/auto.master /etc/hosts.allow. A comment in the new bogus yp.conf
indicated it had been created by NetworkManager. But Networkmanager is not
active:

# chkconfig --list|grep -i netw
NetworkManager  0:off   1:off   2:off   3:off   4:off   5:off   6:off
network         0:off   1:off   2:on    3:on    4:on    5:on    6:off

Did hald or something like that run some NetworkManager stuff? How could
this happen, or rather, how do I prevent this from ever happening again?

mahalo,
Dave