Well, after a week or so the dvd is back in the box and the game unistalled, again....
Although there are some great mods out there i just miss the idea that things are fixed.
On my first patrol i sank 6 ships, returned to port only to ctd after 4 hours of play.
Another attempt left me with no UI, just white rectangles where the buttons were supposed to be.
So i'm gonna play SH4 TMO again and made a mark in my agenda to check this game again in 6 months..
Thanks all for the great tips and help with installing the mods!