Bad Protection stones...

[TNTCREEPY]

Every time I log on to this server, my house and melon farm is griefed and the protection stones are gone.
Or they are there sometimes but when I go to move them they turn into the normal drops not themselves...

Example:

Coal Protection stones = Coal drop

[DJAlphaWolf]

Yes this is a recent glitch that has come up with protection stones. I believe the problem has been fixed if you buy a new protection stone and place it.

However, I may be wrong.