Artillery plotting??

[Copper]

Ok... picture this if you will. In a game against Cargol I had an 81mm Obs and a 120mm Obs. The 81mm Obs had a clear LOS to his target area. After 3 minutes his rounds started to fall. In the middle of my defence about 200 meters from where he had targetted. I re-adjusted the target (green line) the artillery landed in the same (wrong) place. By this time he was out of ammo so I targetted the 120mm Obs on my original intended area to target and the same thing happens... the shells land in the middle of my own troops 200 meters away.

There is no smoke between me and my target.. the line is blue.. when I change target I get the green line.

Ive no idea why this happened... any suggestions.