No.
One question, one answer... no details on your install. So now for the twenty questions:
1. Where do you have the game installed?
2. Which version do you have of SH4 - it should be v1.5 with the U-Boat Mission, which you probably do
3. Did you empty the Save folder after activating the mod?
4. Do you have LAA or similar activated properly on the SH4.exe?
5. Are you shelling-out to Windows to do other tasks while running the game?
That's enough for now, so only one fourth of the twenty questions...