[Problem] Npc's going under ground when aggroed.

[r-log]

I disabled mmaps but with no luck, fyre sent me his own db files but the problem still persists. It happens at almost all the instances and dungeons. Firelands bosses and mobs doesnt go underground, and dragon soul works too. But the stonecore (evertyhing falls through) zul aman first three mobs at the enterance fall through. Its like pathfinding is bugged somehow, and mobs get negative z coordinate so they run underneath you at the right x,y coordinates. But its still strange because in zul aman all other mobs are working correctly, only the mobs that are elevated in some way like standing on stairs etc..