At first it was just this weired foot thing that made the problems: Now i tryed to fix it by reenveloping the whole msh and it look now like this:
So what i did:

I enveloped the unit and in XSI all looked fine.

So i looked the weights, and freezed M.

Now i wanted to show you a pic about how fine it looks, and the unit's msh is moved up and left!!

This Softimage is kidding me. I had this so often. I modify a msh, Freeze m and envelope and after i reimport it the msh is somewhere else!!!!!!

Can someone tell me why this Software is always doing this weired thing with my Models????
You can see at the shadow volume where the model was first, when i exported it

Its not the software, its the user. The image with the misplaced feet looks like you've been moving bones around. 'Freeze M' does nothing for weights and 'Freeze' will remove your envelope operator, you don't want to do that. Your model jumping around was probably caused by you shuffling things or freezing transforms inside the hierarchy, accidental or intentional. I would just suggest starting over in a fresh scene, but I would save a weight preset first. Follow the guides for setting up new characters for SWBF2 and you should have no trouble.