Since I had a working BWS (total hapiness), I decided to change the screen resolution with widescreen. When I changed 1680x1050 to 1260x787 I got the 1628 error again. When I changed the resoltion back to 1024x768, I was able to play the game again.
I'll try a bigger install again, without using widescreen.
The setup in Total hapiness worked. So it must be one of my mods that causes the problem. But since I use standard configurations in the mod-list, it must be a corrupted file I guess.