Silent Hunter IV: U-boat Missions attacking problem

[BuddyFromMoon]

Hello, fellow sailors!

When i engage some kind of a ship (Manually of course), i set the range, AOB then wait 30sec and set the range and AOB again, then i find the speed too automaticly (I would find it manually, but i can't with the damn u-boat, because you can't set it manually) anyway, when i set the torpedo settings and i'm ready to fire, then i always check the "attack map", just in case. Now the problem is that when i check it, then the torpedos course is off (Bearing).
I have always done it, it has always worked, but that damn u-boat screws everything up, i can't hit anything with u-boats, only with US submarines.
Does the u-boats have diffrent targeting system? Or the same?

(Hope you understand, what i'm trying to explain)

Good hunting!