Strange going ons?

I know other people have had this problem of domain names going astray from the files localdomains and userdomains but mine is being a nightmare now.

Three times yesterday and twice today already - once within 15 minutes of recifying the fault.

Out of curiosity I found a script hackcheck and ran it.

Listed the following:

passwd: Unknown user name 'xfs'.
Locking password for user daemon
passwd: Sucess
fileutils passes checksum
findutils passes checksum
net-tools passes checksum

The question is - is this normal?

Many Thanks