Play around with monster flags and immunities.Well for some reason the monsters walk around fields, walls, bombs on the Mystic Spirit server I have. The other ones the creatures go right through the field as if its nothing(it doesn't even do damage to them).
It's up, 0.4 < 1.0, so it's from 0.4 up to 1.0.lord the progression from 04 down to the start or 1.0 was a mass of confusion and changes :S
Play around with monster flags and immunities.