I usually ignore stubbornness based on lack of intellect, but as these are public forums and many people get to read them, i will reiterate for one final time:
The unlimited health and so on script Raivshard links here DOES break the game. English.
It does so by making entire effing categories of mobs get unlimited health; ie unkillable. Irreversibly.
Just as i stated, twice, already. English. Best i can do