Vertices messing up on export

I’m trying to learn modelling for Source, since I needed to do some modifications to the stock citizen models, so I decompiled a model, imported it into XSI, exported it back without any changes, recompiled, and this is what I get.
Can anyone point me out where have I gone wrong?


Corrupted rigging. Though i don’t use xsi so can’t say why.

I used to use XSI. This happened a lot with XSI and exporting to source. For some reason xsi doesn’t “Freeze” the vertices when exporting. the only way i know to get around this is exporting the mesh to an .obj then importing then rerigging again. (it shouldn’t be to hard.)