Slackware :: Files Disappear & Are Reverted To Original?

After 2 weeks of work to restore my server to working condition (after a failed HDD) I am facing a very strange problem. Basically, random files (config, scripts, etc) are either going mising or are reverted to original states. Example1: This morning, I went to use VNC to remote login in my server. I couldnt start the VNC server. I used ssh to login and searched for a lock file (.pid) or anything else preventing VNC from starting, only a few minutes later to open rc.local_shutdown and discover that it was only containing:

Code:
#!/bin/sh
#
# /etc/rc.d/rc.local: Local system initialization script.
#
# Put any local startup commands in here. Also, if you have
# anything that needs to be run at shutdown time you can
# make an /etc/rc.d/rc.local_shutdown script and put those
# commands in there.
All my custom commands were gone...

Example2: Yesterday, I was still using my NFS shares to play music and movies. All worked perfectly. A few minutes ago, I tried to mount the NFS shares on my laptop but it did not work. I used ssh again to login in the server and discovered that nfsd was not running. I tried to start it and it said that there were no exports to share (or something like that). I opened /etc/exports and it was PLAIN empty!! However, I had a export.orig file in /etc... SO somehow, something erased my exports file but care to create a backup of it!

Question: What could do such stupid stuff? Hints: I did not install anything. I did not fool around with anything. The server was unpowered between yesterday and today.