Custom Zones - Z Axis Problem

[KhaN]

Currently, our problem is as follow :
- Flat zones (Command or DB edit) : NPC move correctly
- Hills zones (Command or DB edit) : NPC have problem with Z axis (you see them jump)

Im not a coder, but i think its something related to NPC and Z axis refresh in code, better for me to explain my idea (take in note i have zero clue how pathing work) :"When NPC move from one WP to another, maybe it doesnt -get- the Z coords between those 2 points (NPC should virtually create a segment between those 2 points to know what its Z axis coords should always be while moving)."