I don't know if this applies in your case, but one of the most impactful pastimes us humans do on a computer is to shell-out to the desktop to look something up, and then go back to the game. Today's Windows might release the resources the game is using when that happens, or move them. Silent Hunter 4 does not deal with that very well, and will introduce quite a few anomalies when it happens. Also, each of the repairs that your submarine needs done (if they are repairable by the crew) have a set time frame for the device, and the amount of damage done to it. Say something takes an hour to repair, and you leave the game after 45 minutes of repair to that system, when you next re-enter the game, that "clock" for a one hour repair has re-set to zero. Of course, if the repairs seem to have "frozen", Saving, exiting and re-entering the Saved game are necessary to un-stick the clock, so it is difficult to determine where the fault lies at times like that, and then there are the times that the computer system has run out of resources for the game, and the repair team seems to be at the bottom of the food chain... then again, as fireftr18 says "The simulation is like that."...
