I am currently playing a scenario where I had 2 81mm mortar spotters firing smoke, each one fired for about 30 seconds of the previous turn. At the end of the turn, rounds that had landed but not started smoking all started spewing smoke. I then launched my infantry assault the next turn under a nice protective smoke blanket. Shortly after my infantry got into the open all the smoke disappeared, even though the mortars were firing continuously. It seems that the game registered the rounds that hit near the end of the turn as starting to smoke earlier than they actually should have. This makes it very difficult to launch an assault using 81mm mortars for smoke cover because the smoke just doesn't stay around that long. After a little bit the smoke from the current turns rounds started to appear.
Has this been brought up before? If it has, is there a solution in the works?