Weapons not firing correctly??

[Imp]

My question is this, is there a difference in the programming when the computer tells weapon X to fires in meters and when it tells weapon X to fire in yards?

No
You seem stuck on this, as well as the check mentioned above units & I am assuming this will not take the shot if little chance of hitting/damaging. If it was stationary probably would have fired, if moving & no giro little chance of hitting so it did not bother. In your turn as its now stationary all will most likely fire. Firing from a moving vehicle in this era takes skill & your units are low experience.