Silent hunter 3 Savegame problems

[Askesim]

I have a problem with game saves
When I make a savegame in a single mission, and then load this savegame again
the enemy becomes totally passive in the loaded save game, Ships do not shoot back, and does not try to avoid my submarine or anything.
The enemy is totally passive.!?
It happens in all loaded saves in simglemissions.

First I had a DVD version of the game, but now with a digitaldownload I have the same problem.
With GWX 3 gold its the same

Am I the only one with this problem?
The problem has existed on all my PCs through time

Have a nice day