It's almost certainly the cheat you were using, even though you've turned it off it could have affected those particular enemies/objects in an unexpected way. Try loading a save you made before enabling the cheat (a hard save rather than a save state if possible), this time not using the code at all, and see if it's fixed. If you have both a save state and hard save from before activating the cheat then you can just load the hard save and then the save state if that'll save you time.
"I think that the problem with this video is it is highly derivative of many popular bands within the genre. Although when viewed on its own merits, it does have a deeper groove. However what it has in groove, it lacks in originality. One can't help but be reminded of such bands as Pearl Jam, White Zombie, Suicidal Tendencies and other bands that bear the mantle of so called "Alternative Rock". One is even reminded of Lorie Anderson when she wore curlers. Hehehmhm! This video speaks less to the heart and more to the sphincter. In closing, I think Korn would do well to learn more from -"