[TorpX]

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)

This may or may not help, but I think a 30 sec. interval is too short for any kind of accurate speed estimate. I usually wait at least 3 minutes, unless the range is very short.